Antibodies Directed Against CD127

ABSTRACT

The invention relates to antibodies directed against CD127, the alpha chain of the interleukin 7 (IL-7) receptor IL-7R), and which have antagonist properties for IL-7-IL-7R interaction, may present cytotoxic activity against CD127 positive cells but do not increase the maturation of dendritic cells (DCs) induced by TSLP, a cytokine also using CD127 as part of its receptor. Alternatively, or in addition, these antibodies do not induce the internalization of CD127 and/or inhibit the IL7-induced internalization of CD127. According to another aspect of the invention antibodies are provided which recognize a human CD127 epitope comprising sequences from the 2b site of CD127, in particular the epitope comprising comprises the human CD127 sequences of domain D1 and of the 2b site of CD127, in particular the epitope comprises at least one sequence from D1 comprising SEQ ID No: 115 (in particular comprising SEQ ID No: 110) and/or SEQ ID No: 111 and/or a sequence from the 2b site comprising the sequence of SEQ ID No: 116 and optionally also comprises SEQ ID No: 117 (in particular comprises SEQ ID No: 111). The antibodies of the invention are suitable for use in order to remedy to a condition diagnosed in a human patient which results from pathogenesis related to lymphopoiesis, when IL-7 signalling pathways provide contribution to said pathogenesis, especially when an increase in the maturation, more precisely the upregulation of costimulatory molecules, of dendritic cells is undesirable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.16/532,000, filed Aug. 5, 2019, now U.S. Pat. No. 11,440,964, issued onSep. 13, 2022, which is a Divisional of U.S. patent application Ser. No.15/317,355, filed Dec. 8, 2016, now U.S. Pat. No. 10,428,152, issuedOct. 1, 2019, which is a National Phase of PCT/EP/2015/062993, filedJun. 10, 2015, which are incorporated herein by reference in theirentireties.

REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY

The content of the electronically submitted sequence listing in XLM file(Name B10744BAA_SEQ LIST_ST26.xml; Size: 182,925 bytes; and Date ofCreation: Jun. 2, 2023) filed with the application is incorporatedherein by reference in its entirety.

SUMMARY

The invention concerns the field of antibodies directed against thealpha subunit of the receptor for interleukin7 (IL-7), designated CD127or p90 IL-7R or IL-7Ralpha or IL-7Rα- sometimes also noted IL-7Ra-,especially of the alpha chain of the receptor for human IL-7 expressedon human cells. These antibodies have antagonist properties forIL-7-IL-7R interaction, may present cytotoxic activity against CD127positive cells but do not increase the maturation of dendritic cells(DCs) induced by TSLP, a cytokine also using CD127 as part of itsreceptor. Alternatively, or in addition, these antibodies do not inducethe internalization of CD127 and/or inhibit the IL7-inducedinternalization of CD127. According to another aspect of the inventionantibodies are provided which recognize a human CD127 epitope comprisingsequences from the 2b site of CD127, in particular the epitope compriseshuman CD127 sequences of domain D1 and of the 2b site of CD127, inparticular the epitope comprises at least one sequence from D1comprising SEQ ID No: 115 (in particular comprising SEQ ID No: 110) anda sequence from the 2b site comprising the sequence of SEQ ID No: 116and optionally also comprises SEQ ID No: 117 (in particular comprisesSEQ ID No: 111).

Accordingly the antibodies of the invention are suitable for use inorder to remedy to a condition diagnosed in a human patient whichresults from pathogenesis related to lymphopoiesis, when IL-7 signallingpathways provide contribution to said pathogenesis, especially when anincrease in the maturation, more precisely the upregulation ofcostimulatory molecules, of dendritic cells is undesirable.

Biochemistry

CD127 is common to the IL-7 receptor (IL-7R) and to the TSLP receptor(TSLPR). The IL-7R is constituted of a heterodimer of CD127 and thecommon gamma chain (γc) of interleukin receptors. The common gamma chainγc is sometime referred to herein and in the literature as CD132. IL-7Ris bound by Interleukin 7. The TSLP receptor is a heterodimer of CD127and cytokine receptor-like factor 2 (CRLF2). The TSLP receptor is boundby TSLP. In the literature, TSLPR is sometimes used to designate boththe CRLF2 chain of the receptor, and the CD127/CRLF2 complex. In orderto avoid confusion, in what follows TSLPR usually designates thecomplex.

CD127 (Swiss Prot accession number P16871) may exist in four isoforms.The canonical isoform, also termed H20 (Swiss Prot P16871.1) is asingle-pass transmembrane protein and has 459 amino acids consisting,from N- to C-terminal, of a 20 amino-acid signal peptide, a 219 aminoacid extracellular domain, a 25 amino-acid transmembrane domain and a195 amino-acid intracellular domain. Other isoforms share the sequenceof all of (or most of) the extracellular domain of H20 and displayvaried C-terminal sequences. Isoforms 2 and 4 are secreted (Swiss ProtP16871-4 and P16871-3), while isoform 3 (Swiss Prot P16871-2) is also atransmembrane protein. The sequence of CD127, without the signalpeptide, is provided herein as SEQ ID No: 57. When referring to numberedamino acids of CD127 in the present application, said sequence willserve as reference for the numbering. CD127 is reported to have thesequence of SEQ ID No:113, and its extracellular domain, when the signalpeptide is removed, has the sequence of SEQ ID No: 114. Unless otherwisestated, the numbering used herein for amino acids of CD127 is thenumbering from SEQ ID No:114.

CD127 is a Cytokine Receptor Homology class I (CRH I) receptor. As iswell known in the art, the extracellular domain of these receptorsconsists of two fibronectin 3 domains, termed D1 and D2. The precisecrystallographic structure of CD127 has been published and discussed ine.g. McElroy et al., 2009; McElroy et al., 2012 and Walsh, 2012 and inparticular has been disclosed as protein structure data in the ResearchCollaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB)database, with the accession number 3UP1. D1 is generally considered tobe involved in the binding with IL-7, while D2 is involved in thebinding to the γc chain (and also with IL-7). Importantly, the site 2bof domain D2, essentially consisting of amino acids 109 to 127 of SEQ IDNo: 114 (see Walsh, 2012) is critical for the CD127-γc interaction, inparticular to allow or increase binding of CD127 with γc in the presenceof IL-7. In particular, mutations at P112 and L115, which have beenidentified in patients suffering from Severe combined immunodeficiency(SCID), are thought to destabilize the hydrophobic core of the D2 domainwhich likely results in their pathogenic feature. As said above, the 2bsite consists essentially of amino acids 109 to 127; the skilled personwill appreciate that the extremities of such a domain may notnecessarily be defined unambiguously with a single-base precision andthat the 2b site may be understood to comprise, at either or both endsof the mentioned sequence, 1, 2, or 3 more or less amino acids.Therefore, when referring herein to the 2b site of CD127, this should beunderstood to refer to a sequence of CD127 starting at position 106,107, 108, 109, 110, 111 or 112 and ending at position 124, 125, 126 or127; in particular to such a sequence which is thought or shown toconstitute an essential binding site with the γc chain of the IL7-R, inparticular in the presence of IL-7.

IL-7R signalling. Binding of IL-7 to IL-7R triggers the activation ofseveral signalling pathways, including the Janus kinases (JAK)-1 and -3,signal transducer and activator of transcription 5 (STAT5) andphosphatidylinositol 3-kinase (PI3-k). STAT1 and STAT3 pathways arereported to be activated, although they do not seem to be the mainpathways. The activation of the STAT5 pathway is required for theinduction of the anti-apoptotic protein Bcl-2 and the prevention of theentry of the pro-apoptotic protein Bax in the mitochondrion and thus forsurvival of thymic developing T cell precursors. The activation of thePI3-k pathway results in the phosphorylation and cytoplasmic retentionof the pro-apoptotic protein Bad.

TSLPR signalling. Thymic Stromal Lymphopoietin, (TSLP) is an epithelialCell Cytokine that is active in lymphopoiesis and in particular isinvolved in regulation of development of cells of the immune system,said regulation impacting in particular the maturation of said cells.Human TSLP (Genbank accession number AF338732) is a factor which exertspolarization of dendritic cells and promotes T and B cell proliferationand differentiation. TSLP also suppresses the generation of Treg cells(Lei et al., 2011).

TSLP-induced signaling pathways have been shown to be different, at themolecular level, from IL-7-induced pathways. In particular, while TSLPbinding to its receptor also activates Jak-1, it does not activate Jak-3but does activate Jak-2. These differences are consistent with theobservation that Jak-1 associates with CD127, shared by both receptorswhile Jak-2 associates with CRLF2 and Jak-3 with γc (Rochman et al.,2010). The activation of the STAT5 pathway is also reported forTSLP-induced signaling (Zhong et al., 2014). One major effect of TSLP isto lead to the activation of dendritic cells, inducing theoverexpression of costimulatory molecules such as CD80, therebypromoting TH-2 mediated inflammatory responses (Reche et al., 2001).

Cellular Biology

“CD127-positive cells” designates cells expressing CD127 at their cellsurface. In most cases, CD127-positive cells express CD127 in a complexforming the IL-7R (IL-7R-positive cells) and/or in a complex forming theTSLPR (TSLPR-positive cells). CD127 is expressed by various cells,including by both memory and naive T cells. CD127 is in particularexpressed by effector T cells (Teff), including resting and memory Tcells, and by immature B cells, but is especially not expressed byresting natural regulatory T cells (natural Treg). IL-7Rα is essentialfor promoting thymocyte differenciation and clonal expansion oflymphocytes.

The importance of the IL7-CD127 pathway for naïve T-cell homeostasis isunderlined by several recent studies showing that expression levels ofmembrane-bound IL-7Rα on conventional CD4⁺ T cells correlate withfrequencies of recent thymic emigrant (RTE)-CD4⁺ T cells in healthyindividuals and HIV-infected patients as well as in patients with MS(Albuquerque et al., 2007) (Broux et al., 2010). IL-7Rα is also acomponent of the TSLP receptor. The secretion of TSLP by Hassall'scorpuscles, structures composed of epithelial cells in the thymicmedulla, has been demonstrated to condition CD11c⁺ myeloid dendriticcells (MDCs) to induce the differentiation of thymocytes into Treg(Watanabe et al., 2005a). Accordingly, signals from the IL-7 receptorare required for Treg development as shown in IL-7Rα knockout mice(Mazzucchelli et al., 2008). In (Haas et al., 2011), the authors showeda reduced IL-7Rα expression on conventional T cells and upregulated IL-7plasma levels together with reduction of recent thymic emigrant-Tregfrequencies and Treg function in MS, without clear genetic influence(Haas et al., 2011).

Dissecting how IL-7 regulates its cognate receptor membrane traffickingis crucial to the in-depth understanding of the role of IL-7/IL-7R inlymphocyte function. Previous studies have suggested that IL-7stimulation of T cells leads to surface down-modulation of CD127 within30 minutes, possibly because of receptor internalization. At later timepoints (2-6 hours), IL-7 was shown to induce transcriptionaldown-regulation of CD127. However, the actual dynamics of CD127internalization and the regulation of trafficking mechanisms by IL-7remain to be elucidated (Henriques et al., 2010). It was also suggestedthat IL-7-induced signaling is dependent on CD127 internalization andthat subsequent receptor degradation relies on JAK3 activity and ismediated by both proteasomes and lysosomes.

Physiopathology

Dendritic cells express high levels of costimulatory molecules aftermaturation, such as CD80, which promotes T cell mediated immuneresponses. They also produce the cytokine TARC (CCL17), which induceschemotaxis in T cells. As such, mature dendritic cells contribute to thephysiopathology of several immune-mediated diseases where T cellresponses are at play, as for example in asthma, rheumatoid arthritis,colitis, multiple sclerosis and uveitis. Mature dendritic cells alsoplay a key role in the rejection process of cells, tissues or organallografts. Therefore many therapeutic strategies aim at preventingdendritic cells maturation.

The presence or absence of costimulatory molecules on antigen-presentingcells (APCs), such as dendritic cells significantly influences thequalitative and quantitative nature of an immune response.Overexpression of CD80 by dendritic cells causes DC maturation andinceases memory T cell activation (Bour-Jordan et al., 2011).Mechanistically, interaction of CD28 with CD80 occupies the centralcluster of the immunological synapse and is colocalized with the engagedTCR, thereby stabilizing the immune synapse (Dustin and Shaw, 1999)(Grakoui et al., 1999). The interaction between CD28 and CD80 actuallygenerates the appropriate spacing for TCR to efficiently interact withHLA molecules (Shaw and Dustin, 1997).

Multiple sclerosis (MS) is an inflammatory demyelinating disease of thecentral nervous system (CNS). The appearance of demyelinating patches inthe CNS of patients with MS is associated with an inflammatoryinfiltrate mainly composed of macrophages and T lymphocytes. On amechanistic level, the MS is considered as a autoimmune disease. MS istypically considered as a disease primarily mediated by CD4+ T cells.Particular subsets of CD4+: Th1 and more recently Th17, were implicatedin the pathophysiology of the disease. At present, it is still difficultto assign specific roles to each subpopulation Th1 and Th17.Furthermore, inhibition of leucocyte trafficking by antagonism of thealpha4 (α4)-integrin has now been validated as a therapeutic approachfor the treatment of inflammatory diseases such as MS and inflammatorybowel disease (IBD) and as well for the treatment of atherosclerosis(Zhi et al., 2014). α4β7 is expressed on a more restricted set ofleucocytes including activated macrophage, subsets of lymphocytes, NKcells, mast cells and eosinophils.

Human IL-7 induces strong expression of α4 and β7 integrins in vitro onhuman T lymphocytes and dramatically increases the frequency of human Tlymphocytes expressing α4, β7 and α4/β7 integrins (FIG. 19 ), which arerequired for T lymphocytes homing and retention in non-lymphoid tissuessuch as intestine, brain and skin (Denucci et al., 2009; Gorfu et al.,2009).

Naive T cells are partly responsible for acute rejection of transplantedorgans and tissues. These cells can be controlled by currentimmunosuppressive drugs (calcineurin inhibitors) and by monoclonalantibodies that block costimulation (anti-adhesion, CD80/86 inhibitors).Memory T cells are also responsible for transplant rejection. Memory Tcells accumulate in man due to the acquired immune history, mainlyformer reactions against viruses. It has been shown that memory T cellscan be reactivated by alloantigens as a result of “heterologousimmunity”, which is the cross-reaction of our anti-viral defenses withalloantigens (Adams et al., 2003). Heterologous immunity represents apotent barrier to tolerance induction since memory T cells, in contrastto naive T cells, are programmed to activate quickly, with a reducedrequirement for costimulatory signals. Memory T cells may also beinvolved in chronic rejection. Beside their role in organ and tissuetransplantation, naïve and memory T cells are also co-responsible formany autoimmune diseases. This is the case for ulcerative colitis(Shinohara et al., 2011), rheumatoid arthritis, psoriasis orgraft-versus-host disease.

Furthermore, several malignant cells have been shown to display IL-7R.This is the case for Sezary cutaneous lymphoma (60% of them), orchildhood acute lymphoblastic leukemia in which about 15% of the casesdevelop gain-of-function mutation in CD127, rendering these tumorspartially IL-7 dependent (Shochat et al., 2011).

The depletion of T lymphocytes has been an obvious immunosuppressiveapproach to counteract allograft rejection or fight autoimmunity.However, total T cell depletion might not be favorable for the inductionof immunological tolerance. Targeting T cell subpopulations orselectively activated T cells, without modifying Treg cells, couldconstitute a pro-tolerogenic approach (Haudebourg et al., 2009). CD127may thus be regarded as a potential attractive therapeutic target formonoclonal antibodies (Mabs) aimed at modulating immune responses sincesuch monoclonal antibodies could have the potential of depletingeffector but not regulatory lymphocytes. It has been assumed accordinglythat they might show efficacy in transplantation, autoimmunity (Michelet al., 2008) and malignancies by antagonizing access of IL-7 to IL-7-Rand thereby limiting T and B cell function and growth.

A therapy with a monoclonal antibody against CD127⁺ cells thatinterferes with the IL-7 pathway could fulfill that goal byeliminating/neutralizing naïve and memory T cells and/or reducing theirnumber while preserving Treg cells or by eliminating or reducing thenumber of CD127-positive malignant cells. A therapy with a monoclonalantibody against CD127⁺ cells might however act as a double edge swordif it leads to dendritic cells activation. Indeed, CD127 is alsoexpressed by dendritic cells in association with CRLF2, forming the TSLPreceptor. In the presence of TSLP, dendritic cells get activated andpromote T cell-mediated immune responses. Some monoclonal antibodiesagainst CD127, presumably by modifying the way TSLP interacts with TSLPreceptor, have the property to increase the maturation of dendriticcells induced by TSLP (as shown FIG. 7 with the medium condition). As aconsequence, a therapy with a monoclonal antibody against CD127 thatwould not increase the maturation of dendritic cells induced by TSLPwould present a therapeutic advantage. It would present the benefit ofIL7R blockade without the drawback of activating dendritic cells in aninflamed environment containing TSLP.

In a publication (Racapé et al., 2009) the authors analysed the interestof IL-7 receptor alpha (IL7Rα) as a potential therapeutic target intransplantation. Having reviewed the expression of IL-7Rα on various Tcells and IL-7 responsive cells, the authors determined whethertargeting memory T cells expressing IL-7Rα could prolong allograftsurvival in mice and conclude that targeting IL-7 or IL-7Rα wouldadvantageously spare Treg cells. Among the perspectives, the authorspointed out that targeting either IL-7 or IL-7Rα in therapeutictreatment might have different consequences on the survival of the cellsexpressing CD127 and might elicit different type of lymphopenia. Thequestion of the effects of antibodies that would be directed againstIL-7Rα depending upon whether they would be blocking or neutralizing orcytotoxic antibodies was also posed from a conceptual point of view. Theauthors nevertheless did not show having obtained and assayed suchantibodies and rather expressed the need for further study to assess therelevancy of the hypothesis.

In view of the drawbacks of available therapeutic approaches in immunerelated diseases and other diseases involving the IL-7/IL-7Rα such asdifferent types of cancers, including some breast cancers, there isstill a need for further drug candidates, especially for candidatesactive with respect to more selective targets for the purpose ofcontrolling e.g. modulating immune activation in human patients.

In this context, monoclonal antibodies against IL-7Rα having antagonistproperties toward IL-7Rα have been disclosed in WO2010/017468 and theirhumanized versions in WO2011/094259 with a view to treat autoimmunediseases like multiple sclerosis. The described antibodies are said tobe antagonist for IL-7 binding to its receptor, and active againstT_(H)17 and T_(H)1 cells expansion and survival which were said torequire IL-7 interaction with their CD127 receptor. The effect of theseantibodies on the maturation of immune cells, and particularly ofdendritic cells, has not been considered. Besides, these antibodies aresaid not to inhibit TSLP-induced production of TARC (p. 107 ofWO2011/094259). Similarly, anti-CD127 antibodies reported inWO2011/104687 or in WO2013/056984, which are contemplated for use in thetreatment of diabetes, lupus, rheumatoid arthritis and other autoimmunediseases, have not been discussed with respect to their possible effecton the maturation of dendritic cells and their interaction withTSLP-induced signalling has not been reported. In addition, as publishedby Kern et al (Kern et al., 2013; Kern et al., 2015) and as shownherein, the anti-CD127 antibodies of the prior art induceinternalization of the receptor. Since antagonist anti-CD127 antibodiesthat also induce internalization of CD127 fail to control cutaneous typeIV hypersensitivity (FIG. 10 ), whereas antagonist anti-CD127 antibodiesthat do not induce internalization do, it might be that theinternalization process activates the signalling pathway, mitigating theantagonist effect of the antibodies. Last, the antibodies of the priorart recognize an epitope which does not comprise any sequence from the2b site of CD127 (i.e. in particular from amino acids 109-127 of SEQ IDNo:114); and have not been shown to disrupt the binding of CD127 withthe γc chain of the IL7-R.

Despite recent interest in the development of CD127 antibodies, effortshave thus concentrated on the inhibition of IL7-induced IL-7Rsignalling. Nonetheless, TSLP and the TSLPR have been involved in anumber of pathologies. TSLP has been shown to play a role in skin andlung diseases (He and Geha, 2010) and to associate to variouspathologies including airway inflammatory disease and atopic dermatitisin human and mice (Ying et al., 2008) (Jariwala et al., 2011). Inaddition TSLP has been shown to associate to regulation of intestinalimmunity and inflammation (Taylor et al., 2009). Other pathologiesinvolving TSLP and the TSLPR include pediatric B-cell leukemia (vanBodegom et al., 2012), lung- and skin-specific allergic disorders,autoimmunity-related diseases (Roan et al., 2012) and cancer, includingbreast cancer (Olkhanud et al., 2011).

Therefore, while it is abundantly acknowledged in the prior art thatanti-CD127 antibodies are promising candidates for the treatment ofimmunity-related diseases through antagonism of the IL-7-induced and/orIL-7-R mediated mechanisms, and that such antibodies would also bindCD127 in the context of the TSLP receptor and interfere withTSLP-induced and/or TSLP receptor-mediated mechanisms, their possibleinvolvement in maturation of dendritic cells was not questioned and theimprovement consisting in obtaining antibodies that do not display theeffect of increasing the maturation of dendritic cells and/or that donot induce internalization of CD127 and/or that inhibit IL7-inducedinternalization, was never suggested in the prior art.

Following their surprising discovery of the undesired increase inducedby existing anti-CD127 antibodies in the maturation of dendritic cellsinduced by TSLP (although the antibodies inhibit TSLP-induced productionof TARC), the inventors have developed antibodies which do not displaysuch increase and thus are more suitable for treatment of diseases, inparticular of autoimmune diseases. Moreover, the inventors havediscovered that antibodies which do not induce internalization and/orinhibit IL7-induced internalization of CD127 have high efficiency,especially in vivo compared to prior art antibodies such as MD707-13.

The invention provides means suitable in this context, relating tomonoclonal antibodies against IL-7Rα that interfere only negatively withthe TSLP pathway. Accordingly the monoclonal antibodies (Mabs) of theinvention do not increase TSLP-induced dendritic cell maturation,contrary to what was observed by the inventors with conventionalanti-CD127 antibodies. In addition or alternatively, the antibodies ofthe invention do not induce internalization of CD127 and/or inhibitIL7-induced internalization of CD127. In a particular embodiment, theantibodies provided in the invention combine these DC maturation- and/orinternalization-related properties with antagonist activity towardIL-7/IL-7-R signaling. In particular embodiments, the antibodies of theinvention inhibit IL7-induced expression of α4, β7 and α4/β7 integrinsin T cells, in particular in vivo. These Mabs with novel mechanisms ofaction therefore constitute new products for evaluating therapeuticbenefits of CD127 targeting.

Furthermore, the inventors disclose the epitope recognized by apreferred antibody of the invention, thus allowing for straightforwarddevelopment of alternative antibodies and/or fragments orantigen-binding domains thereof or structurally-related antigen-bindingdomains from other types of polypeptides, which bind the relevantepitope and preserve the desired features.

Epitopes from CD127 recognized by N13B2 were identified by array-basedoligo-peptide scanning (sometimes called overlapping peptide scan orpepscan analysis) and comprise the amino acid sequences of human CD127consisting of the sequences of ep1 (SEQ ID No: 110), ep2 (SEQ ID No:111) and ep3 (SEQ ID No:86). This technique uses a library ofoligo-peptide sequences from overlapping and non-overlapping segments ofa target protein and tests for their ability to bind the antibody ofinterest. By combining non-adjacent peptide sequences from differentparts of the target protein and enforcing conformational rigidity ontothis combined peptide (such as by using CLIPS scaffolds) (Timmerman etal., 2007), discontinuous epitopes can be mapped with very highreliability and precision (Cragg, 2011) (Gaseitsiwe et al., 2010).Further determination of the epitope, using proteolysis protectionprocedures, allowed to determine that the conformational epitopecomprises the amino acid sequences of human CD127 having the sequencesof SEQ ID No: 115, SEQ ID No: 116 and SEQ ID No: 117. The epitopetherefore comprises sequences from the 2b site of CD127. Furthermore,the epitope comprises sequences in both domains D1 and D2 of CD127 andmore specifically sequences from the D1 domain along with sequences fromthe 2b site. Epitopes according to the invention are described in moredetail below. In particular, said epitopes consist of SEQ ID No:115 (orSEQ ID No:110), SEQ ID No:116 (or SEQ ID No:86) and SEQ ID No:117 (orSEQ ID No:111) in their conformational arrangement in the native CD127.

In a particular embodiment, the monoclonal antibodies also exert acytotoxic action against target CD127+ cells that also physically reducetheir number (contraction of the subpopulation).

The invention thus concerns a macromolecule, such as an antibody, anantigen-binding fragment of an antibody or a chimeric moleculecomprising an antibody or a fragment thereof, which (i) bindsspecifically the alpha chain of the receptor to IL-7 (designated CD127)through antibody-antigen interaction, especially of the alpha chain ofthe IL-7 receptor expressed by human CD127 positive cells, and which(ii) does not increase the maturation of dendritic cells induced by TSLP(characterized e.g. by increased expression of cell surface antigensCD80 and/or CD40) and/or (iii) does not induce internalization of CD127and/or inhibits IL7-induced internalization of CD127.

In a particular embodiment of the invention, said macromoleculecomprises a VH chain comprising at least one of the following amino acidsequences:

-   -   VHCDR1 SEQ ID No:10;    -   VHCDR2 SEQ ID No:12;    -   VHCDR3 SEQ ID No:14 or SEQ ID No: 48;    -   VH SEQ ID No:22        and/or a VL chain comprising at least one of the following amino        acid sequences:    -   VLCDR1 SEQ ID No:16 or SEQ ID No: 50;    -   VLCDR2 SEQ ID No:18 or SEQ ID No: 52;    -   VLCDR3 SEQ ID No:20;    -   VL SEQ ID No:24.

In particular embodiments, the macromolecule exhibits cytotoxic activityagainst human T cells expressing CD127 (CD127+ cells). In otherembodiments, the macromolecule does not exhibit cytotoxic activityagainst human T cells expressing CD127 (CD127+ cells).

The invention also concerns compositions comprising said macromolecule,methods of obtaining said macromolecules and uses of said macromoleculesand compositions.

As used herein, a macromolecule designates any molecule, especially amolecule of biological origin or a molecule comprising fragments ofbiological origin, having a molecular weight of more than 500 Da.Macromolecules include, but are not limited to, polypeptides andmodified polypeptides such as glycosylated polypeptides and conjugatesthereof. As used herein, a macromolecule which “binds specifically CD127through antibody-antigen interactions” means that the interactionsbetween said macromolecule and CD127 essentially consist in the sameinteractions as these between an antibody specific to CD127 and CD127.In particular, said macromolecule may comprise the residues of theantibody that are involved in said interaction, in a spatialconfiguration allowing the formation of the same chemical bounds withthe CD127 protein. In a particular embodiment, the macromoleculecomprises at least one CDR sequence of a VH chain and/or of a VL chainof an antibody. In a preferred embodiment, the macromolecule comprisesall of the CDR sequences of the VH chain and/or of the VL chain of anantibody. In a preferred embodiment, the macromolecule comprises theentire VH chain and/or the entire VL chain of an antibody.

In particular embodiments, the macromolecule is produced, designed orselected to recognize an epitope defined as follows (defined by at leastone of the following features):

-   -   (a) the epitope comprises sequences, in particular at least 3,        4, 5, 6 or 7 consecutive amino acids, taken from the 2b site of        CD127, in particular from amino acids 109-127 of SEQ ID No:114,        more particularly from amino acids 110-125, 110-120, 112-120 of        SEQ ID No:114, more particularly from amino acids 114-119 of SEQ        ID No: 114 (corresponding to SEQ ID No: 116); in particular, the        epitope comprises SEQ ID No:116, in particular comprises SEQ ID        No:86; in particular, the epitope comprises P112 or L115 of        CD127;    -   (b) in addition to the features of (a) above, the epitope        comprises sequences, in particular at least 3, 4, 5, 6 or 7        consecutive amino acids, taken from the D1 domain of CD127, in        particular from amino acids 1-98 of SEQ ID No:114; in        particular, the epitope comprises the amino acid sequences of        SEQ ID No: 115 (in particular comprises the amino acid sequence        of ep1 (SEQ ID No:110)    -   (c) in addition to the features of (a), and optionally of (b)        above, the epitope comprises sequences, in particular 3, 4, 5, 6        or 7 consecutive amino acids, taken from amino acids 180-220 of        SEQ ID No:114, in particular from amino acids 190 to 200; in        particular the epitope comprises the amino acid sequence of SEQ        ID No:117; in particular comprises the amino acid sequence of        ep2 (SEQ ID No:111);    -   (d) the epitope comprises the sequences of SEQ ID No:115 and the        sequences of SEQ ID No:116, or the epitope comprises the        sequence of SEQ ID No:117 and the sequences of SEQ ID No:116; in        particular the epitope comprises the sequences of SEQ ID No:115,        SEQ ID No:116 and SEQ ID No:117;    -   (e) the epitope comprises sequences of CD127 as defined in        (a), (b) (c) and/or (d) above, and no other amino acid sequences        (of more than 3, 4, or 5 consecutive amino acids) of CD127 than        the ones explicitly mentioned, i.e. in particular, the epitope        comprises only the following sequences from CD127:        -   one sequence taken from site 2b, in particular consisting of            amino acids 109-127 of SEQ ID No:114, or amino acids            110-125, 110-120, or 112-120 of SEQ ID No:114, or amino            acids 114-119 of SEQ ID No:114 (corresponding to SEQ ID            No:116), or the sequence corresponding to SEQ ID No:86,            and/or consisting of a sequence of 3 amino acids or more            than 3, 4, 5, 6, 7 amino acids and of 19 amino acids or less            than 19, 18, 15, 11 amino acids taken from site 2b, in            particular such a sequence comprising P112 or L115 of CD127;        -   optionally, in addition to the sequence of site 2b, one            sequence taken from domain D1 of CD127, in particular from            amino acids 98 of SEQ ID No:114, in particular one sequence            consisting of SEQ ID No:110 or of SEQ ID No:115, and/or            consisting of a sequence of 3 amino acids or more than 3, 4,            5, 6, 7 amino acids and of 20 amino acids or less than 20,            18, 16, 11 amino acids comprising SEQ ID No:115 or comprised            in the sequence of SEQ ID No:115;        -   optionally, in addition to the sequence of site 2b and to            the optional sequence from domain D1 if present, one            sequence taken from amino acids 180 to 220 of SEQ ID No:114;            in particular one sequence consisting of SEQ ID No:111 or of            SEQ ID No:117, and/or consisting of a sequence of 3 amino            acids or more than 3, 4, 5, 6, 7 amino acids and of 20 amino            acids or less than 20, 18, 16, 11 amino acids comprising SEQ            ID No:117 or comprised in the sequence of SEQ ID No: 117;        -   said epitope possibly comprising additional amino acids,            provided these additional amino acids are not taken from the            sequence of CD127 (i.e. provided the epitope does not            comprise more than 3, 4 or 5 consecutive amino acids from            the sequence of CD127 apart from the sequence from site 2b            and possibly the optional sequences from domain D1 and from            amino acids 180-220 of SEQ ID No: 114 described above);    -   (f) the epitope, in addition to the feature described in (a),        (b), (c) or (d) above, does not comprise more than 3, 4 or 5        consecutive amino acids taken from the region 99-108 of SEQ ID        No:114, does not comprise more than 3, 4 or 5 consecutive amino        acids taken from the region 128-179 of SEQ ID No: 114 and/or        does not comprise more than 3, 4 or 5 consecutive amino acids        from the region 220-239 of SEQ ID No:114, in particular does not        comprise more than 3, 4 or 5 consecutive amino acids from either        region 99-108, 128-179 and 220-239 of SEQ ID No:114;    -   (g) the epitope comprises the combination of sequences of CD127        as defined in (a), (b), (c), (d), (e) and/or (f) above, wherein        some amino acids have been mutated, in particular deleted and/or        substituted, in particular substituted by an amino acid with        similar properties (conservative substitutions); in particular,        the epitope consists of or comprises sequences having at least        80%, 85%, 90%, or 95% sequence identity with the sequences of        CD127 as defined in (a), (b), (c), (d), (e) and/or (f) above, in        combination as defined in (b), (c) or (d) where relevant;    -   (h) the epitope is a conformational epitope having the features        defined in (a), (b), (c), (d), (e), (f) and/or (g) above, i.e.        comprises or consists of the sequences as defined in (a), (b),        (c), (d), (e), (f) and/or (g) above in a conformation which        mimics the conformation of said sequences within the native        CD127 (either as a monomer or as a dimer with γc and/or        associated with IL-7);    -   (i) the epitope comprises a fragment of CD127 (i.e. a stretch of        consecutive amino acids) with the features of (a), (b), (c),        (d), (g) and/or (h) above;    -   (j) the epitope has the features defined in (g) above and is        obtained by a technology such as the CLIPS technology which        allows the synthesis of peptide assemblies with predictable        structure.

In particular embodiments of epitopes with the features of (b) and (c),the epitope includes the amino acid sequence of CD127 which isintercalated between the two sequences ep1 and ep2, and optionally donot extend to include any, or do not extend to include more than oneamino acid of the sequence of the human CD127 sequence upstream (i.e.N-terminal of the sequence of ep1) and/or downstream (i.e. C-terminal ofthe sequence of ep2) of these sequences. In other particularembodiments, the epitope is such that none of the ep1 or ep2 sequencesis extended to include any of their adjacent amino acids in the humanCD127 sequence, or to include more than 7, 5 or 1 consecutive aminoacids from their adjacent amino acids in the sequence of human CD127which is intercalated between ep1 and ep2; the extension of the ep1 andep2 sequences may in this case also be limited upstream (of ep1) ordownstream (of ep2) as above. In particular embodiments, the sequencesof CD127 which comprise the epitope sequences above are not extended tocomprise their adjacent amino acids from the human CD127 sequence bymore than 1 amino acid N-terminal or by more than 7 amino acidsC-terminal adjacent to ep1, or by more than 30 amino acids N-terminal or30 amino acids C-terminal adjacent to ep2.

In embodiments where the macromolecule is produced, designed or selectedto recognize an epitope comprising several non-contiguous amino acidsequences of CD127 (i.e. sequences which are not contiguous in theprimary sequence of CD127), it is possible to produce or selectantibodies which recognizes an epitope comprising one of said CD127sequences, and then select among these antibodies those that recognizethe other CD127 sequence(s) (said later selection may also be performedby successive selections if more than two non-adjacent CD127 sequencesare to be recognized).

The present invention also includes the conformational epitoperecognized by the antagonist antibodies of the invention. The presentinvention also includes antibodies that bind this conformationalepitope. The embodiments include a CD127 conformational epitopecomprising (i) the domain having at least 80%, 85%, 90%, or 95% sequenceidentity with SEQ ID NO. 115 and/or the domain having at least 80%, 85%,90%, or 95% sequence identity with SEQ ID NO. 117 and (ii) the domainhaving at least 80%, 85%, 90%, or 95% sequence identity with SEQ ID NO.116. More particularly, the CD127 conformational epitope comprisingamino acid residues 73-79 and/or 114-119 and amino acid residues 193-196of SEQ ID No:114. The present invention includes antibodies that bindthis conformational epitope. In particular embodiments, themacromolecule is produced, designed or selected to recognize aconformational epitope comprising the amino acid sequences of humanCD127 having the sequences of SEQ ID No: 115, SEQ ID No: 116 and SEQ IDNo: 117.

In particular, in the above embodiments, the antibody is raised againstan immunogen which consists of or comprises an epitope as described,i.e. is initially produced by immunization of an animal which is not ahuman, in particular a mammal, with an antigen comprising or consistingof said epitope. Accordingly, the invention also relates to an antigenof which the epitope is as described above, in particular to its use asan immunogen in the production of antibodies and/or to its use inselection and/or testing methods to produce an antibody orantigen-binding fragment or other macromolecule. The invention alsorelates to said methods using said antigen. Since antigens may comprisenon-peptidic constituents in addition to peptidic constituents and/ormay comprise peptidic constituents which do not form part of theepitope, it should be understood herein that, unless otherwise stated orobvious from the context, when referring to the sequence of an antigenand/or to the features of said sequence, said sequence or featuresshould be understood to designate the sequence (or features thereof) ofthe epitope part of the antigen. If the antigen comprises amino acidswhich do not form part of the epitope, said amino acids preferably donot comprise more than 3, 4 or 5 consecutive amino acids of CD127.

Accordingly and unless it appears technically irrelevant, thedefinitions and features disclosed herein with respect to the antibodiesor their fragments similarly apply to any macromolecule of theinvention.

Binding of CD127

In accordance to the invention, “binding” to the IL-7Rα protein refersto an antigen-antibody type interaction and encompasses “specificbinding” properties of the antibodies or antigen-binding fragmentsthereof which specific binding means that the antibodies orantigen-binding fragments bind to the IL-7Rα protein while they do notbind or bind with a significantly weaker affinity to other proteins(e.g. the common cytokine receptor γ-chain). Specific binding ispreferably defined and/or determined in physiological conditions,especially in terms of pH and salt content of the testing solution.Binding and binding specificity can be assayed in accordance with thetests disclosed in the Examples and in particular can be assayed byBiacore, ELISA, or Western Blot analysis.

In a particular embodiment of the invention, the antibodies orantigen-binding fragments thereof target and bind the IL-7-R alpha chainwhen it is complexed in the TSLP-Receptor (with CCRF2; Genbank accessionNumber AF338733; Reche et al., 2001).

In a particular embodiment, the antibodies or fragments thereof orchimeric molecules of the invention bind to CD127 as an isolated proteinwith a dissociation constant (Kd) lower than 5E-10 M. In a preferredembodiment, the dissociation constant (Kd) is lower than 1E-10 M orlower than 9E-11 M, or lower than 5E-11 M.

In particular embodiments, the antibodies or fragments thereof orchimeric molecule or other macromolecule of the invention binds to anantigen of human CD127 comprising the sequences of ep1 (SEQ ID No: 110)and/or ep2 (SEQ ID No: 111). In particular embodiments, the antigencomprises a fragment of human CD127 comprising both ep1 and ep2 (i.e.the antigen comprises the sequences of ep1 and ep2 and the intercalatedsequences of human CD127). In other embodiments, the antigen comprisesonly ep1 and ep2 sequences from human CD127, possibly in addition toother sequences from other origin, which are distinct from human CD127sequences. In yet other embodiments, ep1 and/or ep2 sequences areextended to include a few additional amino acids from human CD127, inparticular up to one amino acid N-terminal to ep1, up to 7 amino acidsC-terminal to ep1, up to 1, 10, 20 or 30 amino acids N-terminal to ep2,up to 7; 10, 20 or 30 amino acids C-terminal to ep2. Particular antigensinclude: an antigen as above, preferably comprising both ep1 and ep2,wherein the sequence of CD127 comprising ep1 does not extend to comprisethe amino acids adjacent to said sequence in the sequence of humanCD127, or does not extend to comprise more than 1 amino acid N-terminalor more than 7 amino acids C-terminal of ep1 in the sequence of humanCD127; and an antigen as above wherein the sequence of CD127 comprisingep2 does not extend to comprise the amino acids adjacent to saidsequence in the sequence of human CD127, or does not extend to comprisemore than 30 amino acids N-terminal or more than 30 amino acidsC-terminal of ep2 in the sequence of human CD127; and antigens havingboth these features. In particular embodiments, the antibodies orfragments thereof or chimeric molecule or other macromolecule of theinvention binds to an antigen of human CD127 comprising the sequences ofSEQ ID No: 115, SEQ ID No: 116 and SEQ ID No: 117.

In some embodiments, the antigen does not overlap with or does notcomprise an epitope of IL-7R that is recognized by a monoclonal antibodyselected from the group consisting of C1GM, C2M3, P3A9, P4B3, P2D2,P2E11, HAL403a and HAL403b (described in WO 2011104687 A1). In someembodiments, the antibody is raised against an antigen or binds to anepitope which does not comprise any, or does not comprise some ofresidues I82, K84, K100, T105, and Y192 of interleukin-7 receptor alpha,in particular does not comprise K100 and/or does not comprise T105. Insome embodiments, the antigen or epitope does not comprise K194, or doesnot comprise any or does not comprise all of the residues selected fromthe group consisting of residues D190, H191, and K194 of human IL-7R. Inparticular embodiments, the antigen or epitope comprises neither I82 norK84, or comprises neither K100 nor T105, or does not comprise Y192, orcomprises neither D190, H191, Y192 nor K194.

While CD127 is common to both the IL-7R and the TSLPR, it must be notedthat an anti-CD127 antibody will not necessarily recognize (i.e. bind toin suitable conditions) CD127 in both contexts. Moreover, even if theantibody binds to CD127 both in the context of the IL-7R and the TSLPR,it will not necessarily have the same effect on the IL-7-IL-7Rinteraction and the TSLP-TSLPR interaction. It could, for example,prevent the binding of IL-7 to IL-7R and not the binding of TSLP toTSLPR. Furthermore, the binding of the antibody to either receptor mayhave different effects, beyond the different effects on ligand-receptorinteraction. Indeed, the binding of the antibody might modify theconformation of the receptor, independently of the ligand or incombination with the ligand, and thereby activate or inactivate thereceptor. The effect may be different for either receptor and it mayactually be inverted: an antibody which inactivates the IL-7R mayactivate the TSLPR, and vice-versa.

As used herein, activating a receptor means triggering at least some ofthe biochemical changes that occur upon binding of the ligand to itsreceptor. These changes may include modification of the receptorstructure (e.g. dimerization); phosphorylation of the receptor andrecruitment and/or phosphorylation of receptor-bound proteins (such asJanus kinases, STAT transcription factors etc) and/or changes to thecellular localization of the receptor (e.g. receptor internalization).As used herein, deactivating a receptor means preventing, or reverting,at least some of the biochemical modifications associated with thebinding of its ligand to the receptor. For instance, a receptor may beconstitutively activated (i.e. activated even in the absence of aligand) and deactivated in the presence of an agent such as the antibodyof the invention. Alternatively, or additionally, ligand-inducedactivation may be completely, or partially, inhibited by deactivatingthe receptor. Deactivation may therefore occur, among other mechanisms,through preventing binding of the ligand (and subsequent “activation”events), and/or preventing structural changes associated with thebinding of the ligand (e.g. dimerization) and/or modification of thecellular location of the receptor (e.g. the deactivating agent maytrigger receptor internalization and/or degradation and thus preventactivation by the ligand).

Absence of Increased TSLP-Induced Dendritic Cell Maturation

Antibodies of the invention may bind CD127 in the TSLP receptor (i.e.may bind CD127 when it is in a complex with the CRLF2, forming the TSLPreceptor). Therefore, the antibodies of the invention may interfere withTSLP-induced and/or TSLP receptor-mediated signaling.

The inventors have surprisingly found that existing antibodies directedagainst (or which recognize) CD127 in the TLSP receptor and whichdisplay some antagonism with TSLP-TSLPR interaction neverthelessincrease the maturation of dendritic cells induced by TSLP: saidmaturation is higher in cells treated with TSLP and the antibodies thanin cells treated with TSLP alone. These conventional antibodies increaseTSLP-dependent dendritic cell maturation. In preferred embodiments, theantibodies or fragments of the invention do not synergize with TSLP forthe maturation of immune cells, in particular dendritic cells. In otherwords, the antibodies of the invention do not increase the maturation ofimmune cells induced by TSLP. This effect is particularly desired on thematuration of dendritic cells.

It should be emphasized that the capacity of anti-CD127 antibodies toinhibit TSLP-induced production of TARC cannot be considered a validpredictor of a negative (or at least non-positive) effect of theantibodies on TSLP-induced signaling and its downstream consequences (inparticular the maturation of dendritic cells). Indeed, as the inventorshave discovered, even antibodies efficiently inhibiting TSLP-inducedproduction of TARC may increase TSLP-dependent maturation of dendriticcells as measured by expression of CD40 or CD80 with the TSLPR.

TSLP-induced dendritic cell maturation can be measured by the expressionof cell marker CD40 and/or CD80 (Inaba et al., 1995; Watanabe et al.,2005b) as a marker which is a determinant of the maturation of someimmune cells, especially of the so-called TH-2 differentiation observedin some autoimmune diseases, asthma and transplantation. In particularembodiments, the increase in dendritic cell maturation induced by TSLPis assessed by determining an elevated expression of the cell surfacemarker(s) CD40 and/or CD80 in TSLPR-positive cells treated with TSLP andwith the macromolecule of the invention compared with TSLPR-positivecells treated with TSLP alone.

In a particular embodiment, the macromolecules, in particular theantibodies or fragment thereof, which do not increase TSLP-induceddendritic cell maturation do not increase expression of CD80 by morethan 25% when compared to stimulation with TSLP alone (withoutmacromolecule). Preferably, the expression of CD80 is not increased bymore than 20%, preferably not by more than 10% and even more preferablynot by more than 5%. In a particular preferred embodiment, theexpression of CD80 is not increased or is decreased in cells stimulatedwith TSLP and with the macromolecule when compared to cells stimulatedwith TSLP alone.

In a particular embodiment, the macromolecules which do not increaseTSLP-induced dendritic cell maturation do not increase expression ofCD40 by more than 50% when compared to stimulation with TSLP alone(without macromolecule). Preferably, the expression of CD40 is notincreased by more than 25%, preferably not by more than 10% and evenmore preferably not by more than 5%. In a particular preferredembodiment, the expression of CD40 is not increased or is decreased incells stimulated with TSLP and with the macromolecule when compared tocells stimulated with TSLP alone.

Measurement of dendritic cells maturation is also illustrated in theexamples (see in particular Example 9) and can be performed according toany standard method known from the skilled person, in particular anymethod suitable to determine CD80 and/or CD40 expression on dendriticcells, as a marker of dendritic cell maturation.

In order to assay the properties of anti-CD127 antibodies with respectto absence of unwanted potentiation of TSLP signaling, cells expressingthe TSLPR, such as mammalian pro B cells (such as BA/F3 cellsillustrated herein), may be used.

Inhibition of IL7-Induced Expression of α4, β7 and α4/β7 Integrins

In particular embodiments, the antibodies (or macromolecules) of theinvention inhibit IL7-induced expression of α4, β7 and α4/β7 integrinsin vitro. IL7-induced expression of α4, β7 and α4/β7 integrins, as usedherein, designates either or both the increase in the level ofexpression of α4 and β7 integrins and the increase in the number orratio of T lymphocytes expressing α4, β7 and/or α4/β7 integrins. Theinhibition may be partial, i.e. the level of expression of α4, β7 andα4/β7 integrins in the presence of IL7 is increased over baseline level(i.e. the level with neither antibody nor IL7) in the presence ofantibodies, but less than in the absence of antibodies; or theinhibition may be complete, i.e. the level of expression of α4, β7 andα4/β7 integrins in the presence of IL7 and of the antibody is no higherthan baseline level.

In particular embodiments, the antibodies of the invention inhibitexpression of α4, β7 and/or α4/β7 integrins in vitro, i.e. the level ofexpression of α4, β7 and/or α4/β7 integrins is lower in cells treatedwith antibodies (and with and/or without IL7) than in untreated cells(i.e. without antibody or IL7). The extent of inhibition may bedose-dependent. The inhibition of expression may be measured as setforth in the Examples section, which the skilled person may adapt e.g.to specific antibodies, antibody fragments or antigen-binding domains orother macromolecules disclosed herein and/or to specific disease modelsas needed.

In preferred embodiments, the antibodies (or macromolecules) of theinvention inhibit expression of α4, β7 and/or α4/β7 integrins in vivo.As used herein, this expression means that (i) the expression of α4, β7and/or α4/β7 integrins, (ii) the number and/or ratio of α4, β7 and/orα4/β7-positive T-lymphocytes and/or (iii) the engraftment of α4, β7and/or α4/β7-positive T-lymphocytes is reduced in samples obtained fromanimals treated with antibodies relative to untreated animals. As usedherein, engraftment designates the incorporation of grafted tissue orcells into the body of the host, a process which typically occurs over atime period of a few hours to a few days. In particular embodiments, theanimal is a mammal, in particular a non-human mammal, especially amouse. In particular embodiments, the animal is a human. In particularembodiments, the effect is observed on human lymphocytes injected in arecipient animal, preferably an immunodeficient mouse. In particularembodiments, two weeks after injection of human PBMC in immunodeficientmice, the average percentage of integrin β7-positive T cells is reducedby at least 25%, preferably by at least 50%, in antibody-treated micerelative to untreated mice. In particular embodiments, two weeks afterinjection of human PBMC in immunodeficient mice, the average percentageof integrin β7-positive engrafted T cells is reduced by at least 25%,preferably by at least 50%, and even more preferably at least 70% inantibody-treated mice relative to untreated mice. The effect of theantibody or macromolecule of the invention may be determined using themethods put forth in the Examples section, in particular Example 16 forthe expression of α4/β7 integrins and engraftment, which the skilledperson may adapt as needed e.g. to the specific antibody, fragment orantigen-binding domain thereof or other macromolecule and/or to aspecific disease model.

Inhibitors of CD127 Internalization

Internalization is the cellular process by which a cell surface receptorsuch as CD127 is transported inside the cell cytoplasmic space (possiblyin/at the surface of intracellular compartments or membranes) and thusis no longer accessible from the extracellular space, i.e. theinternalized receptor may not be directly contacted by a ligand in theextracellular space. A ligand, whether a natural ligand of the receptoror any artificial ligand or other molecule bound to the receptor, may beinternalized together with the receptor. Most receptors undergo constantinternalization and their cell surface expression is maintained constanteither through the replacement of internalized and degraded receptors bynewly synthesized/maturated receptors or through direct recycling, i.e.transport of the internalized receptor back to the cell surface.

Some stimuli may lead to increased rate of internalization and/ordecreased rate of replacement/recycling, thus leading to a net decreasein cell surface expression of the receptor. As used herein, IL7-inducedinternalization of CD127 designates the decrease of cell surfaceexpression of CD127 induced by the presence of IL7 (or observed in thepresence of IL-7) in the extracellular medium, as observed in vitroafter a limited time of incubation in order to exclude longer-termeffects such as transcriptional down-regulation. Said limited time istypically in the order of tens of minutes, preferably less than 2 hours,more preferably less than 1 hour and even more preferably 45 minutes orless, 30 minutes or less or 15 minutes or less.

In a preferred embodiment, the antibody of the invention inhibits theIL7-induced internalization of CD127. Thus, when incubated with theantibody of the invention, the presence of IL7 induces no decrease inthe cell surface expression of CD127, or induces a less strong decreasein the cell surface expression of CD127 than cells incubated withoutantibodies. In particular embodiments, when incubated with antibodies ofthe invention, the level of CD127 cell surface expression when cells areincubated at 37° C. for 15 minutes with 5 ng/mL IL7 is at least 80%,preferably at least 90% of the cell surface expression level in cellsincubated without IL7. In vitro, the cell surface expression ispreferably measured after a limited time as indicated above. Besides, asmost cellular internalization processes are inhibited at lowtemperature, the effect is usually best observed at physiologicaltemperature, in particular 37° C. However, it is also contemplated toincubate cells at low temperature, in particular 4° C.

It is known that antibodies to a receptor may induce internalization ofthe receptor, meaning that the cell surface expression of the receptoris decreased in the presence of the antibody. This may arise inparticular by inducing a change in the conformation of the receptorwhich mimics that induced by the natural, internalization-inducing,ligand, and this effect may depend on the epitope recognized by theantibodies. As used herein, ‘an antibody induces the internalization ofCD127’ means that cells incubated in the presence of an antibody displaydecreased cell surface expression of CD127 compared to cells incubatedin the absence of the antibody. Cell surface expression is preferablymeasured in vitro after a limited incubation time and in temperatureconditions as mentioned above. In a preferred embodiment, the antibodyof the invention does not induce the internalization of CD127. Thus, thecell surface expression of CD127 in cells incubated in the presence ofthe antibody is not reduced, or is not significantly reduced, relativeto cell surface expression in cells incubated in otherwise identicalconditions, but in the absence of the antibody. In particularembodiments, when incubated at 37° C. for 30 to 45 minutes in thepresence of 50 ng/mL of antibody, the level of CD127 cell surfaceexpression is at least 80%, preferably at least 90% of its level incells incubated in the absence of the antibody. This effect may beobserved in the absence of IL7 (in both antibody-treated and -untreatedcells), in the presence of IL7, and/or both.

Either of the two CD127 internalization-related feature described above(i.e. inhibition of IL7-induced internalization or non-induction ofinternalization) may contribute to increased efficiency of theantibodies, while the combination of both features is possibly even moreefficient. Disclosed herein is an antibody representing a preferredembodiment, wherein in the presence of both IL7 and said antibody, thecell surface expression of CD127 is not significantly decreased. In suchpreferred embodiments, after a 45-minute incubation in the presence of50 ng/mL of antibody, including 15 minutes in the presence of 5 ng/mLIL7, at 37° C., the level of CD127 cell surface expression is at least80%, preferably at least 90% of its level in control cells, incubated inmedium containing no antibody or IL7.

Disruption of CD127—γc Chain Interaction

According to a particular embodiment, the macromolecule, in particularan antibody or antigen-binding fragment thereof, of the invention maydisrupt the binding of CD127 to the γc chain of the IL7-R. This meansthat, under conditions (in particular chemical and physical conditions)where CD127 and γc chain are bound together in the absence of antibody,and in particular in the presence of IL-7, the presence of the antibodysignificantly reduces said bond. In particular embodiments, in thepresence of antibody and of IL-7, CD127 does not bind to γc. Inparticular, in the presence of the antibody and of IL-7, the amount ofγc chain found associated with (or bound to) CD127 is less than 80%,preferably less than 50%, even more preferably less than 25% or 10% ofthe amount bound in the absence of the antibody (or in the presence ofanother anti CD-127 antibody such as MD707-13) in otherwise identicalconditions, in particular in the presence of IL-7. Such a feature of theantibody may be assessed in particular by co-immunoprecipitationmethods, well known to the skilled person for testing the interaction ofproteins and illustrated herein in Example 21. In particular, cells maybe incubated in the presence or absence of the tested antibody, thensolubilized in conditions allowing for the preservation of proteincomplexes, and the resulting lysate may be subjected to an anti-CD127immunoprecipitation and the presence of γc in the CD127-containingimmunoprecipitated complex assessed by western blotting using anti-γcantibodies (conversely, the immunoprecipitation may be performed usinganti-γc antibodies and the presence of CD127 assessed using anti-CD127antibodies).

One method for obtaining such antibodies is to raise said antibodiesagainst an epitope comprising sequences from the 2b site of CD127, or toselect antibodies which recognize such an epitope. Indeed, the bindingof the antibody to this site, critical for interaction with γc, islikely to disrupt, e.g. by competition or steric hindrance, theinteraction of γc with CD127.

It is also possible, in particular, to select antibodies having thisdesirable feature, from anti-CD127 antibodies, e.g. from an antibodylibrary (including when this library was not obtained by using animmunogen comprising sequences of the 2b site), through conventionalscreening procedures known to the skilled person and readily adaptableto such end. In particular, for example, CD127 (or its extracellulardomain alone) may be bound to 96-well plates or similar substratescommonly used for such screening. The antibodies constituting thelibrary may be added individually, each in one well, and the γc chainadded to each well. After washing the plates, the presence of γc in eachwell may be tested, e.g. by methods based on fluorescence. In wellscontaining an antibody with the desired feature, no γc (or small amountsthereof) will be detected. It is obviously possible to modify thisprocedure, e.g. to rather spot the antibodies on a solid substrate inindividual spots; allow CD127 to bind to the spotted antibodies, andallow γc chain to bind to the thus immobilized CD127 chains.

Antagonist Towards IL-7-IL-7R Interaction

According to a particular embodiment, a macromolecule, in particular anantibody or antigen-binding fragment thereof, of the invention furtherhas antagonist properties toward interleukin 7 (IL-7) therebyantagonizing access, i.e. binding of IL-7 to CD127 on CD127 positivecells.

“Antagonist properties towards IL-7-IL-7R interaction” means thatantibodies or antigen-binding fragments thereof of the invention, whichtarget the IL-7Ralpha, have the effect of preventing the accessibilityof the IL-7 receptor expressed on CD127 cells, especially human effectorT cells, in particular human memory T cells, for its binding partnerIL-7, especially human IL-7. As a result of antagonizing binding ofIL-7, the antibodies of the invention or their functional fragments leadto lymphopenia by preventing IL-7-dependent thymic T cells generation.

The antagonist properties may be in particular antagonism toward IL-7Rsignaling induced by IL-7. An antagonist of IL-7R signaling induced byIL-7 can be identified by measuring the inhibition of STAT5phosphorylation as described in the Examples. The IL7-inducedphosphorylation of STAT5 is a marker of IL7R activation and an antibodyantagonizing IL7-IL7R interaction is expected to decrease IL7-inducedphosphorylation of STAT5.

In particular embodiments, the macromolecule of the invention is anantagonist of IL-7R signaling induced by IL-7. In a particularembodiment, the macromolecule of the invention inhibits IL7-inducedphosphorylation of STAT5. In preferred embodiments, the inhibition ofSTAT5 phosphorylation is greater than 50% at antibody concentrations aslow as 50 ng/ml and/or the inhibition of STAT5 phosphorylation isgreater than 80% at antibody concentrations as low as 100 ng/ml.Inhibition of STAT5 phosphorylation may be assessed by methods known tothe skilled person and in particular by the method set forth in theexamples section (in particular Example 3).

“Antagonist for Binding of TSLP”

Since the antibodies of the invention bind CD127 in the IL-7R, they mayalso bind CD127 in the TSLPR and, particularly by steric hindranceand/or by competition on common binding sites, they may inhibit thebinding of TSLP to the TSLPR. In other words, the antibodies of theinvention may present antagonist activity for the binding of TSLP.

“Inhibitor of TSLP-Induced TARC Production”

In a particular embodiment, the antibodies of the invention may inhibitTSLP-induced TARC production of CD127-positive cells. As mentionedabove, TSLP-stimulated dendritic cells produce elevated levels of TARC.This may result from their binding to the TSLPR and their potentialaction as antagonists of TSLP binding.

In a particular embodiment, the antibodies of the invention, and theirantigen-binding fragments have been selected for their ability to notincrease their maturation (maturation being e.g. determined an increasedexpression of CD40 and/or CD80 cell surface marker).

The level of TSLP-induced TARC production may be lower in cells treatedwith TSLP together with the anti-CD127 antibodies or fragments thereofor chimeric molecules as described herein than in cells treated withTSLP alone. In other words, the macromolecules of the invention may beinhibitors of TSLP-induced TARC production. In an embodiment of theinvention, the antibody or fragment thereof or chimeric molecule asdescribed herein decreases the levels of TARC production. In aparticular embodiment of the invention, the level of TARC production incells treated with TSLP and the antibody, fragment or chimeric moleculeis reduced by more than 10%, preferably more than 20%, compared to thelevel in cells treated with TSLP alone, at antibody concentrations aslow as 1 μg/ml. Measurement of TARC production is illustrated in theexamples (in particular Example 9) and can be carried out onCD127-positive immune cells, in particular dendritic cells, from a bloodsample using any standard method known from the skilled person.

“Cytotoxic Activity”

In a particular embodiment of the invention, the antibodies of theinvention or their antigen-binding fragments directed against the CD127molecule present in the IL-7 receptor have furthermore the property ofbeing cytotoxic against human cells, especially human T cells expressingsaid receptor. Human cells expressing CD127 as a chain of IL-7 receptor,which are the target of the antibodies of the invention and fragmentsthereof, are mainly T lymphocytes and more precisely are subpopulationsof effector T lymphocytes including naïve and memory T cells but are notregulatory T cells (Treg), especially not resting natural Treg. Memory Tcells are generated as a result of antigen priming and mainly defined bytheir functional characteristics, including ability to undergo recallproliferation upon re-activation and differentiation into secondaryeffector and memory cells. Similarly, the targeted TSLP receptor (as acomplex including the IL-7-R alpha chain) regulates T helper lymphocyte,B cell and dendritic cell differentiation.

According to an embodiment of the invention, the antibodies andantigen-binding fragments thereof, having “cytotoxic activity against Tcells” or cytotoxic properties (cytotoxic antibodies) give rise todepletion in the effector T cell population by killing these cells andaccordingly reduce the number of these cells when administered. To thecontrary, these antibodies do not alter the subpopulation of regulatoryT cells or do not alter it to a significant extent, allowing the Tregcells to perform their function. In this context, in a particularembodiment, it has been observed that the ratio of regulatory T (Treg)versus effector T (Teff) cells raises following administration ofantibodies of the invention. In a particular embodiment, antibodies ofthe invention enable to raise said ratio of about 10% or more. In aparticular embodiment, the increase in the ratio of Treg versus Teff isof about 20%.

According to a particular embodiment of the invention, the cytotoxicantibodies show Antibody-Dependant Cellular Cytotoxicity (ADCC).According to another embodiment, the antibodies of the invention have noADCC properties. Antibody ADCC potential was considered positive whenspecific cytoxicity was superior to 10%. ADCC properties can beevaluated in an ADCC assay such as the test described in the Examples(in particular Example 10). When the antibody is a rat antibody theeffector cells used in the ADCC assay are LAK (Lymphokine-activatedkiller) cells of rat. When the antibodies are humanized the ADCC assaycan be carried out on human NK cells.

The antibodies of the invention which have both cytotoxic and antagonistproperties for CD127 positive cells enable cumulative effects of theseproperties with respect to the depletion of effector T cells, especiallyof memory T cells especially, thereby enabling a stronger depletion(exhaustion of the pool of CD127+ cells) and corresponding reduction inthe number of target T cells.

The paragraphs above as well as the Examples describe how to test forthese functional characteristics. The following sections will detailvarious structural characteristics and possible modifications of theantibodies or fragments or chimeric molecules. In light of theseguidances, the skilled person will be able to obtain antibodies orfragments having the structural characteristics below along with thedesired functional characteristics, in particular starting from anantibody which has the desired functional characteristics, such asN13B2, because in some cases it can be predicted that adopting some ofthe structural features will not modify the functional features and/orby testing for the loss of functional characteristics after theintroduction of a new structural characteristic. Furthermore, with thedisclosure herein of the epitope recognized by the antibody, thedevelopment of other antibodies sharing the same functional features isa routine procedure, since antibodies raised against the same or asimilar epitope could be selected for their ability to provoke similareffects upon binding to CD127. Again, straightforward testing proceduresbeing disclosed herein, the skilled person may use these tests to selectsuitable antibodies.

In a preferred embodiment of the invention, the macromolecule is N13B2or an antibody having at least one of the CDRs of N13B2, or thefragments are fragments of N13B2. Accordingly, the invention relates toan antibody or fragment thereof which VH comprises at least one of thefollowing amino acid sequences, or one of their preferable humanizedvariants described below:

-   -   VHCDR1 SEQ ID No:10;    -   VHCDR2 SEQ ID No:12;    -   VHCDR3 SEQ ID No:14;

and/or which VL comprises at least one of the following amino acidsequences, or one of their preferable humanized variants describedbelow:

-   -   VLCDR1 SEQ ID No:16;    -   VLCDR2 SEQ ID No:18;    -   VLCDR3 SEQ ID No:20.

In a particular embodiment, the macromolecule comprises at least 2, 3, 4or 5 of the CDR sequences of N13B2 i.e. VHCDR1 SEQ ID No:10, VHCDR2 SEQID No:12, VHCDR3 SEQ ID No:14, VLCDR1 SEQ ID No:16, VLCDR2 SEQ ID No:18and VLCDR3 SEQ ID No:20, any number of which may be replaced by one oftheir preferable humanized variants described below. In a particularembodiment, the macromolecule comprises all six CDR sequences of N13B2,any number of which may be replaced by one of their preferable humanizedvariants described below. In particular embodiments, the macromoleculecomprises the VH chain having the amino acid sequence of SEQ ID No:22and/or the VL chain having the amino acid sequence of SEQ ID No:24. Inparticular embodiments, the macromolecule comprises the heavy chainhaving the amino acid acid sequence of SEQ ID No:2 and/or of SEQ ID No:6and/or the light chain having the amino acid sequence of SEQ ID No:4.Other particular embodiments relative to the VH and VL chains arehumanized variants disclosed below. In a particular embodiment, theconstant chain has the sequence of the rat IgG1 Fc chain of FIG. 12(Uniprot P20759) and/or the sequence of SEQ ID No:34.

Fragments

An “antigen-binding fragment” of an antibody of the invention is a partof the antibody, i.e. a molecule corresponding to a portion of thestructure of the antibody of the invention that exhibits antigen-bindingcapacity for alpha chain of the IL-7 receptor for human IL-7, possiblyin its native form; such fragment especially exhibits the same orsubstantially the same antigen-binding specificity for said antigencompared to the antigen-binding specificity of the correspondingfour-chain antibody. Advantageously, the antigen-binding fragments havea similar binding affinity as the corresponding 4-chain antibodies.However, antigen-binding fragment that have a reduced antigen-bindingaffinity with respect to corresponding 4-chain antibodies are alsoencompassed within the invention. The antigen-binding capacity can bedetermined by measuring the affinity of the antibody and of theconsidered fragment. These antigen-binding fragments may also bedesignated as functional fragments of antibodies.

Antigen-binding fragments of antibodies are fragments which comprisetheir hypervariable domains designated CDRs (Complementary DeterminingRegions) or part(s) thereof encompassing the recognition site for theantigen, i.e., IL-7Ra of human IL-7, thereby defining antigenrecognition specificity. Each Light and Heavy chain (respectively VL andVH) of a four-chain immunoglobulin has three CDRs, designated VL-CDR1,VL-CDR2, VL-CDR3 and VH-CDR1, VH-CDR2, VH-CDR3, respectively. Thus theinvention relates in particular to fragments of antibodies of theinvention, which comprise or consist in all or a selection of CDRs amongVL-CDR1 (SEQ ID No:16), VL-CDR2 (SEQ ID No:18), VL-CDR3 (SEQ ID No:20)and VH-CDR1 (SEQ ID No:10), VH-CDR2 (SEQ ID No:12) and VH-CDR3 (SEQ IDNo:14), their humanized variants disclosed below, or functional portionsthereof, i.e. portions that exhibit the desired binding specificitypreferably with a high affinity for IL-7Ra of human IL-7.

Particular antigen-binding fragments of the invention are fragments ofthe VH chain of an antibody of the invention that combine its CDR1, CDR2and CDR3 domains, in particular those having the amino acid sequencedisclosed herein, including the humanized variants disclosed below.Other fragments of the invention are fragments of the VL chain of anantibody of the invention that combine its CDR1, CDR2 and CDR3 domains,in particular those having the amino acid sequence disclosed herein,including the humanized variants disclosed below. Fragments thatcomprise or consist in VH-CDR3 and/or VL-CDR3, in particular thosehaving the amino acid sequence disclosed herein, including the humanizedvariants disclosed below, or functional portions thereof are especiallypreferred when CDR3 regions appear to be determinant in antigenrecognition specificity.

The skilled person will be able to determine the location of the variousregions/domains of antibodies by reference to the standard definitionsin this respect set forth, including a reference numbering system(Martin, 2001) or by reference to the numbering system of Kabat (Kabatet al., 1992) or by application of the IMGT “collier de perle” algorithm(http://www.imgt.org/IMGTindex/Colliers.html, Lefranc et al., 1999). Inthis respect, for the definition of the sequences of the invention, itis noted that the delimitation of the regions/domains may vary from onereference system to another. Accordingly, the regions/domains as definedin the present invention encompass sequences showing variations inlength or localization of the concerned sequences within the full-lengthsequence of the variable domains of the antibodies, of approximately+/−10%.

In addition, de-immunization residues may be present in the variable CDRdomains of the antibodies or antigen-binding fragments thereof. In aparticular embodiment, the antibody or fragment thereof is deimmunized.

Based on the structure of four-chain immunoglobulins, antigen-bindingfragments can thus be defined by comparison with sequences of antibodiesin the available databases and prior art (Martin, 2001), and especiallyby comparison of the location of the functional domains in thesesequences, noting that the positions of the framework and constantdomains are well defined for various classes of antibodies, especiallyfor IgGs, in particular for mammalian IgGs. Such comparison alsoinvolves data relating to 3-dimensional structures of antibodies.

For illustration purpose of specific embodiments of the invention,antigen-binding fragments of an antibody that contain the variabledomains comprising the CDRs of said antibody encompass Fv, dsFv, scFv,Fab, Fab′, F(ab′)2 which are well defined with reference to (Kabat etal., 1992), (Martin, 2001) and also (Delves et al., 2011) Fv fragmentsconsist of the VL and VH domains of an antibody associated together byhydrophobic interactions; in dsFv fragments, the VH:VL heterodimer isstabilised by a disulphide bond; in scFv fragments, the VL and VHdomains are connected to one another via a flexible peptide linker thusforming a single-chain protein. Fab fragments are monomeric fragmentsobtainable by papain digestion of an antibody; they comprise the entireL chain, and a VH-CH1 fragment of the H chain, bound together through adisulfide bond. The F(ab′)2 fragment can be produced by pepsin digestionof an antibody below the hinge disulfide; it comprises two Fab′fragments, and additionally a portion of the hinge region of theimmunoglobulin molecule. The Fab′ fragments are obtainable from F(ab′)2fragments by cutting a disulfide bond in the hinge region. F(ab′)2fragments are divalent, i.e. they comprise two antigen-binding sites,like the native immunoglobulin molecule; on the other hand, Fv (a VH-VLdimmer constituting the variable part of Fab), dsFv, scFv, Fab, and Fab′fragments are monovalent, i.e. they comprise a single antigen-bindingsite.

Chimeric Antibodies

According to another embodiment of the invention, the antibodies aremodified and are, as a result, chimeric antibodies, comprising domainsor strand(s) of amino acid residues of different antibodies, inparticular antibodies obtained from different animal species, combinedtogether in a functional antibody. In a particular embodiment, themacromolecule of the invention is a chimeric antibody consisting in anassembly of antibody fragments from at least two different species. In aparticular embodiment, a chimeric antibody comprises the constant regionof a human antibody. Such constant regions are illustrated in theexamples by Fc fragments G1 (SEQ ID No:26) or Fc fragments G4 (SEQ IDNo:28) or CL kappa fragment (SEQ ID No:30). Alternatively, human Fcfragments depicted in FIG. 12 (Uniprot P01857, Uniprot P01859, UniprotP01861) and/or with the sequences of SEQ ID No:31, SEQ ID No:32, SEQ IDNo:33 or SEQ ID No:112 may be used. In a particular embodiment, achimeric antibody comprises the variable region of a rodent antibody andthe constant region of a human antibody. In a particular embodiment, achimeric antibody comprises the VH chain with the sequence of SEQ IDNo:2 (N13B2-G1m-VH-FcG1m(E333A)) or the sequence of SEQ ID No:6(N13B2-G4m-VH-FcG4m(S228P)) and the VL chain with the sequence of SEQ IDNo:4 (N13B2-G1m-VL-CLkappa).

Affitins, Anticalins and Other Antibody Mimetics

Macromolecules of the invention also comprise artificial proteins withthe capacity to bind antigens mimicking that of antibodies, also termedherein antigen-binding antibody mimetic. Such proteins comprise affitinsand anticalins. Affitins are artificial proteins with the ability toselectively bind antigens. They are structurally derived from the DNAbinding protein Sac7d, found in Sulfolobus acidocaldarius, amicroorganism belonging to the archaeal domain. By randomizing the aminoacids on the binding surface of Sac7d, e.g. by generating variantscorresponding to random substitutions of 11 residues of the bindinginterface of Sac7d, an affitin library may be generated and subjectingthe resulting protein library to rounds of ribosome display, theaffinity can be directed towards various targets, such as peptides,proteins, viruses and bacteria. Affitins are antibody mimetics and arebeing developed as tools in biotechnology. They have also been used asspecific inhibitors for various enzymes (Krehenbrink et al., 2008). Theskilled person may readily develop affitins with the required bindingproperties using methods know in the art, in particular as disclosed inpatent application WO2008068637 and the above-cited publication, inparticular the generation of phage display and/or ribosome displaylibraries and their screening using an antigen as disclosed herein.Anticalins are artificial proteins that are able to bind to antigens,either to proteins or to small molecules. They are antibody mimeticderived from human lipocalins which are a family of naturally bindingproteins. Anticalins are about eight times smaller with a size of about180 amino acids and a mass of about 20 kDa (Skerra, 2008). Anticalinphage display libraries have been generated which allow for thescreening and selection, in particular of anticalins with specificbinding properties. The skilled person may readily develop affitins withthe required binding properties using methods know in the art, inparticular as disclosed in EP patent EP1270725 B1, U.S. Pat. No.8,536,307 B2, (Schlehuber and Skerra, 2002) and the above-citedpublication, in particular the generation of phage display and/orribosome display libraries and their screening using an antigen asdisclosed herein. Anticalins and affitins maybe both be produces in anumber of expression system comprising bacterial express in systems.Thus, the invention provides affitins, anticalins and other similarantibody mimetics with the features of the antibodies described herein,in particular with regard to binding to CD127, non-induction and/orinhibition of CD127 internalization, maturation of DCs, all of which arecontemplated as macromolecules of the invention. Humanization

In a particular embodiment, the macromolecules of the invention arehumanized antibodies or antigen-binding fragments thereof. Accordinglyhaving been originally obtained in animals, especially in rodents and inparticular in rats, following immunization of animals and production ofmonoclonal antibodies from hybridoma, the antibodies of the inventionare modified in their VH and/or VL sequences by substitution of aminoacid residues, in the framework and optionally in addition in the CDRsequences. The humanization can be performed by resurfacing or by CDRgrafting according to known techniques. Resurfacing is especiallyachieved by the substitution of rodent residues for human amino acidresidues. The substitution is performed in a way that maintains theframework structure of the original antibody and also the CDRspresentation, thereby enabling that the frameworks and CDRs interactionsin the resurfaced antibody preserve native conformation of the surfacecontacting the antigen so that it retains antigen binding affinity.

Preferred embodiments of the antibody of the invention are representedby the humanized versions of the (rat) N13B2 antibody comprising thefollowing light and heavy chains:

The heavy chain of N13B2-h1, having the sequence of SEQ ID No: 36,wherein the CDR sequences of the rat N13B2 have been conserved, as wellas a few other amino acids outside the CDR sequences, and wherein allother amino acids match the sequence of a human antibody. This heavychain has 87.8% identity with a human antibody heavy chain. Thefollowing residues outside the CDR sequences have been conserved: V atKabat position H24 (position 24 in FIG. 23 ; A in the human sequence), Vat Kabat position H37 (position 37 in FIG. 23 ; I in the humansequence), A at Kabat position H49 (position 49 in FIG. 23 ; S in thehuman sequence) and D at Kabat position H73 (position 74 in FIG. 23 ; Nin the human sequence);

The heavy chain of N13B2-h2, having the sequence of SEQ ID No: 38,wherein, compared with the heavy chain of N13B2-h1, amino acids at Kabatpositions H37, H49 and H73, outside the CDR sequences, have beenmodified to match the sequence of a human antibody heavy chain;

The heavy chain of N13B2-h3, having the sequence of SEQ ID No: 40,wherein, compared with the heavy chain of N13B2-h2, the M at Kabatposition H96 (position 100 in FIG. 23 ), within the CDR3 sequence, hasbeen mutated to L to match the sequence of a human antibody heavy chainand/or to avoid post-translational modification. Other possible residuesfor this position include in particular A, F and I and more preferably For I. Accordingly, a possible humanized variant for the CDR3 sequence ofN13B2 VH has the sequence of SEQ ID No: 48.

The light chain of N13B2-h1, having the sequence of SEQ ID No: 42,wherein the CDR sequences of the rat N13B2 have been conserved, as wellas a few other amino acids outside the CDR sequences, and wherein allother amino acids match the sequence of a human antibody. This lightchain has 80% identity with a human antibody light chain. The followingresidues outside the CDR sequences have been conserved: V at Kabatposition L48 (position 48 in FIG. 24 ; I in the human sequence), Y atKabat position L71 (position 71 in FIG. 24 ; F in the human sequence)and F at Kabat position L87 (position 87 in FIG. 24 ; Y in the humansequence);

The light chain of N13B2-h2, having the sequence of SEQ ID No: 44,wherein, compared with the light chain of N13B2-h1, the three aminoacids at Kabat positions L48, L71 and L87, outside the CDR sequences,have been modified to match the sequence of a human antibody lightchain;

The light chain of N13B2-h3, having the sequence of SEQ ID No: 46,wherein, compared with the light chain of N13B2-h2, amino acids Kabatpositions L31 (position 31 in FIG. 24 ) and/or L52 (position 53 in FIG.24 ), within the CDR1 and CDR2 sequences respectively, have been mutatedfrom N to Q and from S to T respectively, to match the sequence of ahuman antibody light chain and/or to avoid post-translationalmodification. Other possible amino acids for the L31 position include Hand R. Other possible mutations for the CDR3 sequence involve conservingthe S in position L52 and mutating the N in position L51 (position 52 inFIG. 24 ) to Q, H, K or R. Accordingly, a possible humanized variant forthe CDR1 sequence of N13B2 VL has the sequence of SEQ ID No: 50, and apossible humanized variant for the CDR2 sequence of N13B2 VL has thesequence of SEQ ID No: 52.

Multi-Functional Antibodies or Fragments

These basic antigen-binding fragments of the invention can be combinedtogether to obtain multivalent antigen-binding fragments, such asdiabodies, tribodies or tetrabodies. These multivalent antigen-bindingfragments are also part of the present invention.

The above-mentioned modifications may be combined where relevant. Inparticular embodiments, the macromolecule is an antibody which is achimeric antibody or an humanized antibody and/or a deimmunizedantibody.

Methods of Obtaining Antibodies of the Invention

An antibody or an antigen-binding fragment thereof of the invention isin particular advantageously raised against a molecule which is theCD127 expressed by human T cells, possibly raised from an immunizationunder the form of native polypeptide or recombinant molecule.

Immunization can be carried out according to the protocol disclosed inthe Examples below: Recombinant CD127 Fc Chimera (10975-H03H SinoBiological, Beijing, China) was used to immunize rats such as rats ofthe LOU/C Igk1a strain available at the University of Louvain, Belgium).Alternatively, an antigen comprising the amino acid sequences of SEQ IDNo:115 (in particular comprising SEQ ID No: 110) and/or of SEQ ID No:117(in particular comprising SEQ ID No: 111) and/or of SEQ ID No:116, saidantigen additionally comprising other sequences, in particular othersequences of human CD127, or not, as disclosed above,_may be used as theimmunogen. Hybridoma were obtained by fusing spleen mononuclear cellswith the LOU rat immunocytoma IR983F, a non-secreting and azaguanineresistant cell line, according to a previously described procedure(Chassoux et al., 1988). Hybridoma were first screened according to thecapacity of the secreted monoclonal antibodies to bind to recombinantCD127 molecule (CD127 Fc Chimera; 10975-H03H, Sino Biological, Beijing,China). Hybridoma were then screened for the capacity of theirmonoclonal antibodies to bind to the CD127 expressed by human T cellsand for the capacity to inhibit induction of STAT-5 phosphorylationinduced by IL-7 on human leukocytes, as exemplified in FIG. 1 , and fortheir capacity not to increase the maturation of dendritic cells inducedby TSLP.

According to a particular embodiment of the invention, a humanizedantibody of the invention is derived from the antibody designated N13B2by mutation of one or more of the CDR region(s) of its Variable Heavychain (VH) and/or of its Variable Light chain (VL), in particular anantibody keeping at least one or two original CDR region among CDR3,CDR2 and CDR1 regions in either of VH and/or VL, said modified antibodyhaving less than 10% of mutated amino acid residues, preferably one orno mutated amino acid residue, in individually considered CDR regionswith respect to the original CDR1, CDR2 or CDR3 region, wherein saidoriginal CDR regions are

-   -   i. VHCDR1 having the amino acid sequence SEQ ID No 10;    -   ii. VHCDR2 having the amino acid sequence SEQ ID No 12;    -   iii. VHCDR3 having the amino acid sequence SEQ ID No 14;    -   iv. VLCDR1 having the amino acid sequence SEQ ID No:16;    -   v. VLCDR2 having the amino acid sequence SEQ ID No:18;    -   vi. VLCDR3 having the amino acid sequence SEQ ID No:20;

Accordingly, the VHCDR3 may have the amino acid sequence of SEQ ID No:48; the VLCDR1 may have the amino acid sequence of SEQ ID No: 50; theVLCDR2 may have the amino acid sequence of SEQ ID No: 52.

In a particular embodiment, an antigen-binding fragment of the inventionis an antigen-binding fragment of the N13B2 antibody which is modifiedas described in the previous paragraphs, said modified antigen-bindingfragment having less than 10% of mutated amino acid residues withrespect to the original antigen-binding fragment.

In view of the teaching provided by the present invention, in order toexpress antibodies of the invention, the skilled person will be able toprepare hybridoma or to use alternative technologies such as expressionlibraries and expression systems, followed by selection of antibodieshaving the structure of those secreted by the hybridoma and having itsproperties, in particular its binding and neutralisation properties.cDNA libraries can adequately be prepared from the RNA expressed inhybridoma of the invention and the appropriate sequences selected andexpressed. Alternatively, cDNA encoding the antibodies of the inventionor their fragments are prepared by synthesis.

“Hybridoma cells” according to the invention are cells generated fromfusion of antibody producing cells (B Lymphocytes) from an animalpreviously immunized with a selected immunogen and fusion partner whichare myeloma cells enabling to provide immortality to the resultingfusion cell. Myeloma cells and antibody producing cells (B cells such assplenocytes) can be of the same origin, and are eukaryotic cells inparticular mammalian cells of the same animal. They can be alternativelyof different origin, thus giving rise to a heterohybridoma. Myelomacells such as the LOU rat immunocytoma IR983F, a non-secreting andazaguanine resistant cell line are chosen among cells that fail toproduce immunoglobulins in order to enable the prepared hybridoma tosecrete only monoclonal antibodies of the desired specificity. Othercells suitable for promoting ADCC such as those described in thefollowing pages for the preparation of the antibodies through expressionin recombinant cells may be used instead of the rat immunocytoma. Suchcells are advantageously cells having a low or no fucosylation capacity.

Preparation of hybridoma suitable for carrying out the invention isperformed according to conventional techniques. Embodiments aredescribed in detail in the Examples of the present application of whichthe particular disclosed features can be adapted to other cells used asfusion partners.

The antigen-binding fragments of the antibody may be obtained startingfrom the antibody, especially by using enzymatic digestion according towell-known techniques including papain or pepsin digestion, or using anyappropriate cleavage technique. They may be alternatively expressed inhost cells modified by recombination with nucleic acid sequencesencoding the amino acid sequence of said fragments, or may besynthesized, especially chemically synthesized. Accordingly, theantibodies of the invention, including the modified antibodies and theantigen-binging fragments of the antibodies can also be prepared byclassical genetic engineering techniques, such as those described bySambrook et al. (Deininger, 1990) and updated versions). The inventionaccordingly relates to the versions of the VH and VL polypeptides thatencompass the signal peptide or not. The signal peptide may be necessaryduring the preparation of the polypeptides in cells.

With a view to use the antibody of the invention or their functionalfragments for administration to a human patient, it might be beneficialto derive humanized monoclonal antibodies or chimeric monoclonalantibodies and/or de-immunized antibodies, from antibodies of theinvention which would be non-primate antibodies such as thoseillustrated in the Examples, especially to lower the immune reaction ofthe receiving host or patient against said antibodies. Functionalfragments of these variant antibodies may be obtained also as humanized,chimeric or de-immunized variants.

An antibody or an antigen-binding fragment thereof, which is a humanizedantibody can also be derived by substitution of amino acid residue(s)present in constant region(s) of variable chains (VH and/or VL) of anon-human antibody of the invention, for human amino acid residue(s)having corresponding location in human antibodies according to standarddefinition and numbering, wherein the substitution level is from 1% to20%, in particular from 1% to 18% of the residues in said frameworkregions. Said constant regions include those of framework regions (FwRs)defined in four-chain antibodies identified in particular by referenceto Kabat numbering.

Particular examples of modified antibodies according to the inventionencompass chimeric antibodies, humanized antibodies and/or ade-immunized antibodies.

A particular modified antibody has modified amino acid residues in theCDRs regions, said modification resulting in a de-immunisation by lossof the T cell epitopes in the variable domain of the non-human antibody.De-immunisation can be performed after determination of the T cellepitopes in the antibody variable domain, especially by in silicoprediction, followed by point mutation in the sequence of the variablechains of the antibody that eliminates the functional T cell epitopes.In a preferred embodiment of the invention, the modification of theCDR(s) regions, especially of the CDR3 regions are limited to the extentnecessary to de-immunisation with a view to administration to the humanbody, e.g. to decrease binding affinity of T cell receptors forHLA-class II/peptide complexes. In a particular embodiment, the CDR3region(s) of the VH and/or of the VL is(are) not modified. In anotherembodiment the FR regions and/or the CH regions are also modified,especially humanized.

Antibodies within the frame of the invention encompass accordingly anantibody based on the above defined features, which is a humanizedantibody especially one obtained by substitution of amino acidresidue(s) present in framework region(s) of an antibody of theinvention, for human amino acid residue(s) having corresponding locationin human antibodies according to standard definition and numbering. Thesubstitution level of amino acid residues in the framework regionsand/or in the CDRs for humanization, including de-immunisation, is from1% to 20% in particular from 1% to 18% of the residues in said frameworkregions and/or CDRs regions. As mentioned above, the humanizationprimarily targets the Framework regions of the original antibodies. Insome cases, humanization may alternatively or also concern CDR region(s)especially CDR1 and/or CDR2 region(s) and is more particularlydesignated as de-immunisation. In particular embodiments, no more thanone amino acid is modified in each CDR region. Examples of humanizedand/or deimmunized antibodies derived from the rat antibody N13B2 aredisclosed herein.

Humanization can hence be achieved considering the human germline Lightchain or Heavy chain frameworks that show the highest sequence identitywith the sequence of the non-human antibody or fragment, and selectingthe amino acid residues, especially residues exposed at the surface inthe antibody, to be substituted in said non-human antibody or fragmentthereof, in order to conform to the corresponding human residue(s). In aparticular embodiment some of or all the FRL and/or some of or all theFRH regions are fully human, i.e., are characteristic of human frameworksequences. In another embodiment selected residues in some or all the FRregions are substituted.

Methods for humanizing antibodies are also well known in the art and aredescribed for instance by Routledege et al. (Edward G. Routledge, 1993).These methods can also apply to antigen-binding fragments, such asscFvs. By way of example, the method known as “resurfacing” consists inreplacing the set of surface residues in the frameworks of the variableregion of a nonhuman antibody with a human set of surface residues,while the method known as CDR grafting consists of transferring the CDRsfrom a non-human antibody into the framework regions of a humanantibody. CDR grafting is generally completed by framework optimization,consisting in the replacement of some residues of the human framework,in order to optimize the binding affinity. The step of frameworkoptimization has been recently simplified by the use of combinatoriallibraries (Rosok et al., 1996) (Baca et al., 1997).

The invention relates in particular to humanized antibodies derived byCDR grafting from the rat N13B2 antibody. Human VH and VL sequenceshaving sequences with strong homology to the VH and VL sequences,respectively, of rat N13B2 were selected in a database. The CDRsequences of N13B2 were grafted onto these human sequences. Someresidues outside the CDR sequences might have a significant impact onantigen recognition or affinity, in particular residues in immediateproximity to the CDRs and residues known as Vernier residues. Asdetailed above and in the Examples section, in particular in Example 12,several versions of the humanized antibodies were tested: the mostconservative where all rat sequences were conserved for the CDR and theabove-mentioned structurally important residues, a version where humansequences were selected for the structurally important residues and theversion closest to the human sequences, where, in addition to thestructurally important residues outside the CDR, a few residues insidethe CDR were modified from the initial rat sequence in order inparticular to prevent post translational modifications such as oxidationor deamidation.

Another recent strategy available for antibody humanization preservesonly the original nonhuman CDR3 sequences of light and heavy chainswhile the remaining sequence is selected from naïve human V genelibraries (Rader et al., 1998).

The chimeric, humanized and/or de-immunized antibodies of the inventioncan belong to any class of immunoglobulins, like the non-modifiedantibodies. Preferably, they belong to a subclass of the IgG class suchas IgG1, IgG2, IgG3 or IgG4.

Methods for preparing recombinant antigen-binding fragments, or chimericantibodies by combining the variable regions of an antibody withappropriate linkers, or with the constant regions of another antibody,are well known in the art.

The antibodies of the invention are said to be monoclonal antibodies,meaning that a composition of these antibodies is homogeneous,especially identical, in terms of antigen-binding specificity andaccordingly in terms of variable region composition. Hence theantibodies may qualify as monoclonal even if they are obtained bytechniques alternative to the technique of hybridoma.

According to another embodiment, the invention also relates to achimeric molecule which comprises an antibody according to any of thedefinition provided herein or an antigen-binding fragment thereof,wherein said antibody or functional fragment thereof is associated witha functionally different molecule. A chimeric molecule of the inventionmay be either a fusion chimeric protein or a conjugate resulting fromany suitable form of attachment including covalent attachment, grafting,chemical bonding with a chemical or biological group or with a molecule,such as a PEG polymer or another protective group or molecule suitablefor protection against proteases cleavage in vivo, for improvement ofstability and/or half-life of the antibody or functional fragment. Withsimilar techniques, especially by chemical coupling or grafting, achimeric molecule can be prepared with a biologically active moleculesaid active molecule being for example chosen among toxins, inparticular Pseudomonas exotoxin A (Risberg et al., 2011), the A-chain ofplant toxin ricin (van Oosterhout et al., 2001) or saporintoxin (Flavellet al., 2006), especially a therapeutic active ingredient, a vector(including especially a protein vector) suitable for targeting theantibody or functional fragment to specific cells or tissues of thehuman body, or it may be associated with a label or with a linker,especially when fragments of the antibody are used.

PEGylation of the antibody or functional fragments thereof is aparticular interesting embodiment as it improves the delivery conditionsof the active substance to the host, especially for a therapeuticapplication. PEGylation can be site specific to prevent interferencewith the recognition sites of the antibodies or functional fragments,and can be performed with high molecular weight PEG. PEGylation can beachieved through free Cysteine residues present in the sequence of theantibody or functional fragment or through added free Cysteine residuesin the amino sequence of the antibody or functional fragment.

The invention concerns also a composition comprising antibodies orfunctional fragments thereof as defined herein, wherein the antibodiesor functional fragments thereof are a homogeneous population ofantibodies or functional fragments thereof or are monoclonal antibodiesor functional fragments thereof.

In some cases it is possible to use a composition of products to obtainthe desired effect, where each of the products in the compositiongenerates at least one desired effect. In the present case, for example,it is possible to combine molecules having an inhibitory effect on theIL-7-IL-7R interaction and molecules having cytotoxic effect againstCD127 positive cells. Such combinations are included in the invention.Importantly, in the invention, the composition of products should notsynergize with TSLP for the maturation of dendritic cells. Usually, thisinvolves combining products of which none individually synergizes withTSLP for the maturation of dendritic cells.

In a particular embodiment, the invention concerns a composition or anassembly of compounds comprising antibodies, fragments or chimericmolecules as described herein, said composition comprising (i) apopulation of antibodies or antigen-binding fragments thereof orchimeric molecules having cytotoxic activity against CD127 positivecells, especially CD127+ T cells and (ii) a population of antibodies orfunctional fragments thereof or chimeric molecules having antagonistproperties towards human IL-7, these populations of antibodies beingeither combined in a mixture or separated and, in this latter option,formulated for combined or sequential administration. The antibodiesand/or functional fragments and/or chimeric molecules do not synergizewith TSLP for the maturation of dendritic cells.

The definitions provided herein especially by reference to theantibodies of the invention, similarly apply to the antigen-bindingfragments thereof except where it is technically obviously not relevant.These definitions also apply to macromolecules (in particular chimericantibodies or chimeric molecules) or compositions comprising theseantibodies or antigen-binding fragments thereof or derived from theseantibodies, as disclosed in the present application. It is furtherspecified that the antigen-binding fragments of the antibodies of theinvention are derived from the antibodies from a conceptual or designpoint of view but may be prepared through various techniques, notnecessarily having recourse to the antibodies as products.

The invention also relates to a nucleic acid molecule encoding amacromolecule according to any of the definitions provided herein. Inparticular embodiments, the nucleic acid of the invention encodes anamino acid chosen from the group consisting of SEQ ID No:2; SEQ ID No:4;SEQ ID No:6; SEQ ID No:8; SEQ ID No:10; SEQ ID No:12; SEQ ID No:14; SEQID No:16; SEQ ID No:18; SEQ ID No:20; SEQ ID No:22, SEQ ID No:24, SEQ IDNo:36, SEQ ID No:38, SEQ ID No:40, SEQ ID No:42, SEQ ID No:44, SEQ IDNo:46, SEQ ID No:48, SEQ ID No:50, SEQ ID No:52, SEQ ID No:54, SEQ IDNo:56, SEQ ID No:110, SEQ ID No:111, SEQ ID No:86, SEQ ID No:115, SEQ IDNo:116 and SEQ ID No:117. In particular embodiments, the nucleic acid ofthe invention comprises or consists in the sequence of SEQ ID No: 1, 3,5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 35, 37, 39, 41, 43, 45, 47, 49, 51,53 or 55.

Such a nucleic acid suitable for the preparation of macromolecules ofthe invention is especially chosen in the group of:

-   -   i. a polynucleotide encoding a VH region and having the sequence        of SEQ ID No 1 or SEQ ID No: 5 or SEQ ID No:54 or the variable        region of a VH region and having the sequence of SEQ ID No:21 or        SEQ ID No: 35 or SEQ ID No:37 or SEQ ID No:39;    -   ii. a polynucleotide encoding a VL region having the sequence of        SEQ ID No 3 or SEQ ID No: 7 or SEQ ID No:56 or the variable        region of a VL region and having the sequence of SEQ ID No:23,        or SEQ ID No: 41 or SEQ ID No:43 or SEQ ID No:45;    -   iii. a polynucleotide encoding a VHCDR1 region having the        sequence of SEQ ID No:9,    -   iv. a polynucleotide encoding a VHCDR2 region having the        sequence of SEQ ID No:11,    -   v. a polynucleotide encoding a VHCDR3 region having the sequence        of SEQ ID No:13 or of SEQ ID No:47,    -   vi. a polynucleotide encoding a VLCDR1 region having the        sequence of SEQ ID No 15 or of SEQ ID No:49,    -   vii. a polynucleotide encoding a VLCDR2 region having the        sequence of SEQ ID No 17 or of SEQ ID No:51,    -   viii. a polynucleotide encoding a VLCDR3 region having the        sequence of SEQ ID No 19.

The invention also relates to a polynucleotide having modifiednucleotides with respect to the sequence of SEQ ID No 1, 3, 5, 7, 9, 11,13, 15, 17, 19, 21, 23, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53 or 55,and which:

-   -   (a) encodes a polypeptide having amino acid sequence of        respectively SEQ ID No 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22,        24, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54 or 56 and/or    -   (b) has at least 85%, preferably at least 90%, more preferably        at least 95%, and most preferably at least 98% or at least 99%        identity over its whole length with one of the polynucleotides        having respectively sequence of SEQ ID No 1, 3, 5, 7, 9, 11, 13,        15, 17, 19, 21, 23, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53 or 55        and/or,    -   (c) is a fragment of the polynucleotide having sequence of        sequence SEQ ID No: 1, 3, 5, 7, 21, 23, 35, 37, 39, 41, 43, 45,        53 or 55, and encodes a polypeptide comprising or consisting of        an antigen-binding fragment.

Polynucleotides of the invention can also be optimized sequences,especially for the expression in host cells. Optimisation techniques inthis field are conventional ones.

Polynucleotide fragments of the invention have advantageously a sequenceof at least 9 nucleotides, in particular at least 18 nucleotides and areshorter than their sequence of origin, especially shorter thanfull-length illustrated VH or VL sequences respectively.

According to a particular embodiment, polynucleotides of the inventionmay advantageously comprise, besides a sequence encoding a macromoleculeaccording to the invention, upstream from the sequence encoding theantibody chains, a sequence encoding a signal peptide allowing secretionof said protein when expressed in a production cell. They may alsocomprise one or more sequence(s) encoding one or more marker peptide(s)for detecting, and/or facilitating the purification of, said protein.

The invention also concerns a vector for the cloning and/or for theexpression of a polynucleotide disclosed herein. In a particularembodiment, the vector of the invention is a plasmid suitable forcloning and/or expressing in mammalian cells, which comprises regulationsequences for transcription and expression.

The invention further relates to cells or cell lines recombined with apolynucleotide of the invention, especially a mammalian or an avian cellor cell line. For example Chinese Hamster Ovary Cells, geneticallymodified to reduce global fucosylation. Indeed, Antibodies lacking corefucosylation show a significantly enhanced antibody-dependentcell-mediated cytotoxicity (ADCC) (von Horsten et al., 2010). Anotherexample is the EB66 cell line which naturally has low fucosylationproperties (Olivier et al., 2010).

Thus the invention also relates to a method of preparing an antibody oran antigen-binding fragment thereof, which comprises:

-   -   (a) obtaining a hybridoma after immunizing an animal, especially        a mammal with the human alpha chain of the human IL-7 receptor,        preferably with an antigen thereof comprising the sequences of        human CD127 with the sequences of SEQ ID No:115 (and/or SEQ ID        No: 110) and/or SEQ ID No:117 (and/or SEQ ID No: 111) and/or SEQ        ID No: 116 (and/or SEQ ID No:86), said antigen comprising other        sequences of human CD127 or not, as disclosed above, and, where        necessary, boosting said animal with the same immunogen,        recovering spleen or lymph node cells from the animal responding        to immunization and fusing said cells with myeloma cells to        isolate monoclonal antibodies and/or    -   (b) expressing polynucleotides coding for such antibodies such        as polynucleotides disclosed herein with their nucleotide        sequence in the recombinant form in cells in conditions enabling        the recovery of antibodies, and    -   (c) recovering antibodies recognizing an epitope as defined        herein, in particular comprising sequences from the 2b site of        CD127 and in particular comprising such sequences and in        addition sequences from the D1 domain of CD127, in particular        antibodies having the desired binding affinity against the alpha        chain of the human IL-7 receptor.

In a particular embodiment of the invention, the antibodies or theirfragment are prepared in cells that present low fucosylation properties,such as EB66 avian cells.

The invention also relates to a method of selection of antibodiescomprising the steps of obtaining, possibly through one of the methodsdescribed herein, antibodies or fragments thereof which specificallybind CD127, in particular an antigen thereof as disclosed above, andselecting among these antibodies those that do not increase theTSLP-induced maturation of immune cells, in particular dendritic cells,that do not induce internalization of CD127 and/or that inhibitIL7-induced internalization of CD127 and/or that inhibit in vitro and/orin vivo expression of α4, β7 and/or α4/β7 integrins. The selection maybe performed using any of the procedures described in the Examplessection to test for increase or decrease of TSLP-induced expression ofcell surface markers CD40 and/or CD80 or to test for effects oninternalization of CD127 or to test for effects on the expression of α4,β7 and α4/β7 integrins. Such tests can conveniently be performed in e.g.96-well plates to allow for fast and efficient screening of a largenumber of candidate antibodies and the readout can be performed byclassical immunostaining and flow cytometry analysis. Thus, theinvention relates to a method of selecting antibodies, antigen-bindingfragments thereof or other macromolecule which comprises or consists ofat least one of the following steps:

-   -   a. Testing (e.g. as described in Example 1, Example 2, Example 6        and/or Example 7) a macromolecule with the binding capacity of        the macromolecule to CD127, in particular to an antigen thereof        as disclosed herein;    -   b. Testing (e.g. as described in FIG. 16 and/or Example 5) the        internalization of CD127 in CD127-expressing cells induced by        the presence of the macromolecule;    -   c. Testing (e.g. as described in FIG. 16 and/or Example 5) the        inhibition by the macromolecule of IL7-induced internalization        of CD127 in CD127-expressing cells;    -   d. Testing (e.g. as in FIG. 5 , FIG. 6 and/or Example 9) the        increase of the maturation of DCs induced by TSLP in the        presence of the macromolecule;    -   and optionally comprising at least one of the following steps:    -   e. Testing (e.g. as in FIG. 1 , FIG. 2 and/or Example 3) the        inhibition by the macromolecule of IL-7 induced signalling, in        particular STAT5 phosphorylation;    -   f. Testing (e.g. as in Example 9, FIG. 5 and/or FIG. 6 ) the        inhibition by the macromolecule of TSLP-induced production of        TARC;    -   g. Testing (e.g. as in Example 16, FIG. 19 and/or FIG. 20 ) the        inhibition by the macromolecule of the expression of α4, β7        and/or α4/β7 integrin expression, in particular cell surface        expression on T-lymphocytes;    -   h. Testing (e.g. as in Example 21, FIG. 28 ) the disruption by        the antibody of the binding of CD127 to the γc chain, in        particular in the presence of IL-7.    -   Each of these testing steps being followed by the selection of        one or more macromolecules having the desired functional        features, as disclosed herein.        As mentioned above, when it is desired that the antibody        recognizes an epitope comprising sequences which are not        contiguous in the sequence of CD127, it is possible to test        successively the recognition of (or binding to) fragments of the        epitope consisting (or essentially consisting) of a single        contiguous sequence of CD127. For example, if it is desired to        obtain an antibody recognizing an epitope comprising sequences        SEQ ID No:115, SEQ ID No:116 and SEQ ID No:117, it is possible        to first select antibodies recognizing an epitope essentially        consisting of SEQ ID No:116, and then secondly to select, among        these first selected antibodies, antibodies recognizing an        epitope essentially consisting of SEQ ID No:115, and then to        select, among these secondly selected antibodies, antibodies        recognizing an epitope essentially consisting of SEQ ID No:117.        Obviously, the order of selection may be modified relative to        this order, provided solely as an example.

Another object of the invention is a pharmaceutical compositioncomprising a macromolecule according to the invention, with apharmaceutical vehicle, wherein said pharmaceutical compositionoptionally further comprises a different active ingredient.

The invention also relates to a composition comprising as an activeingredient, a macromolecule of the invention or a pharmaceuticalcomposition as defined above, in a formulation suitable for controllinghuman CD127 positive cells survival or expansion, in particular humanCD127 positive effector cells, especially CD127+ memory T cells survivalor expansion, especially memory T cells which are both CD127+ and CD8+,or which are both CD127+ and CD4+ cells, when administered to a humanpatient. In a particular embodiment, the composition comprising themacromolecule of the invention as an active ingredient is in aformulation suitable for controlling the differentiation and/ormaturation of dendritic cells when administered to a patient.

A composition of the invention may further comprise an additionalcompound having a therapeutic immunomodulator effect, in particular oncells involved in allergy or autoimmunity. For illustration purposes,exemplary immunomodulators of interest are other monoclonal antibodiestargeting T cells, such as anti-CD3, anti-ICOS or anti-CD28 antibodiesor recombinant proteins or antibodies targeting accessory cells such asCTLA4Ig or anti-CD40 antibodies.

The invention concerns also an antibody or an antigen-binding fragmentthereof or a chimeric molecule as defined or illustrated herein, for useas active ingredient in a combination or add-on therapeutic regimen in apatient in need thereof. Also contemplated is the use of amacromolecule, nucleic acid, cell or cell line of the invention as atherapeutically active ingredient in a combination or in an add-ontherapeutic regimen in a patient in need thereof.

A macromolecule according to the invention, a nucleic acid, vector,cell, cell line, pharmaceutical composition or a composition as definedherein are in particular proposed for use in a human patient fortreating pathologic conditions influenced by immune responses,especially by memory T cells responses. Accordingly, the inventorsproposed that the antibody or antigen-binding fragment thereof, chimericmolecule according to the invention, pharmaceutical composition orcomposition as defined herein be used for the treatment of autoimmune orallergic diseases in particular allergic skin disorders, intestinaldisorders or for transplant rejection or for the treatment of leukemiasuch as acute lymphoblastic leukemia (e.g. T-ALL) or lymphoma such asHodgkin lymphoma, or the treatment of a cancer disease such as breastcancer associated with CD127+ cells, renal cancer, bladder cancer, lungcancer, pancreatic cancer, or for the treatment of a T cell cutaneouslymphoma, such as Sezary lymphoma, or for the treatment of the acutelymphoblastoid leukemia with gain-of-function mutation of theIL-7-R/TSLP pathway.

In various embodiments, the invention is related to the use ofmacromolecules as defined herein in order to deplete CD127-positivecells while preserving CD127-negative cells.

In various embodiments, the invention is related to the use ofmacromolecules as defined herein in order to prevent differentiationand/or expansion and/or maturation of CD127-positive cells, inparticular differentiation, expansion, or maturation induced by IL-7and/or TSLP, while having little or no direct effect on CD127-negativecells.

In a particular embodiment, the invention relates to the use ofmacromolecules defined herein in order to eliminate/neutralize naïve andmemory T cells by interfering with IL-7-induced signaling, whilepreserving Treg cells.

In a particular embodiment, the invention also relates to the use ofmacromolecules defined herein in order to deplete subpopulations oflymphocytes, or other cell populations expressing CD127 (includingnormal or pathologic T and B lymphocytes, NK cells, dendritic cells andother cell types including epithelial cells) as a result of cytotoxicaction of the antibodies, possibly but not exclusively through ADCC(Antibody-Dependent Cellular Cytotoxicity) and optionally through CDC(Complement-Dependent Cytotoxicity).

In the embodiments above, the contemplated used are also applicable tonucleic acids, vectors, cells, cell lines and compositions of theinvention.

By “treatment” or “therapeutic treatment”, it is meant that theperformed steps of administration result in improving the clinicalcondition of an animal or a human patient in need thereof, who suffersfrom disorder(s) associated with the IL-7 pathway, i.e. involving theactivation or proliferation of CD127 positive cells. Such treatment aimsat improving the clinical status of the animal or human patient, byeliminating or alleviating the symptoms associated with the disorder(s)related to the IL-7 pathway, i.e. involving the activation orproliferation of CD127 positive cells. In a preferred embodiment, thetreatment according to the invention enables restoring to health. In apreferred embodiment, said treatment does not have undesired negativeeffects due to increased maturation of immune cells, in particular ofdendritic cells.

The invention includes the use of the macromolecules in the treatment ofpathologic conditions involving the alteration of immune response in ahuman patient leading to dominant tolerogenic state or, to the contrary,lack of tolerance where control of the level of the immune responsewould be needed as well as destruction of malignant CD127-positivecells.

The invention provides means suitable for use in pathologies such asthose induced by transplant rejection, autoimmune diseases, allergicdiseases, respiratory diseases, chronic viral infections, lymphoma,leukemia or other cancer diseases including those resulting from solidtumors (e.g. breast cancer) when these pathologies are associated withCD127 positive cells as well as the IL-7 signalling pathway and where anincrease in the maturation of dendritic cells must be avoided.

In a particular embodiment, the invention relates to the use of amacromolecule, nucleic acid, cell, cell line or composition of theinvention in a human patient for the treatment of an autoimmune diseaseor an allergic disease or for the treatment of leukemia such as acutelymphoblastic leukemia or for the treatment of lymphoma, or for thetreatment of cancer disease, or for the treatment of a chronic viralinfection, or for the treatment of inflammatory diseases, or for thetreatment of respiratory diseases, or for the treatment of symptomsrelated to a transplantation.

In a particular embodiment, the invention relates to a method oftreatment comprising the administration of a macromolecule, nucleicacid, cell, cell line or composition of the invention in a human patientfor the treatment of an autoimmune disease or an allergic disease or forthe treatment of leukemia such as acute lymphoblastic leukemia or forthe treatment of lymphoma, or for the treatment of cancer disease, orfor the treatment of a chronic viral infection, or for the treatment ofinflammatory diseases, or for the treatment of respiratory diseases, orfor the treatment of symptoms related to a transplantation.

Additional features and properties of the invention will be apparentfrom the Examples and figures which follow.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 . Inhibition of IL-7R signaling. Inhibition of IL-7 inducedpSTAT5+ T lymphocyte in dose-response to anti-human IL-7Rα monoclonalantibodies. N13B2 (square), N13E5 (circle) and N13K12 (triangle).pSTAT5(%): ratio (%) of cells positive for phospho-STAT5, as measured byFACS. Dose-dependent inhibition of STAT5 phosphorylation is similar forthe three clones, all three inhibiting phosphorylation efficiently at 50ng/ml (roughly 50% inhibition) and completely at 100 to 500 ng/ml (>95%inhibition).

FIG. 2 . Inhibition of IL-7R signalling by N13B2 mAb. Axes as in FIG. 1. (A) Inhibition of IL-7 induced pSTAT5+ T lymphocyte in dose-responseto N13B2 mAb (squares) as compared to MD707-3 mAb (circles), both inrodent format. (B) Same experiment as in (A) with human IgG1 (square)and human IgG4 (circle) chimeric forms of N13B2 in the presence of 0.1(empty symbols) or 5 ng/ml (full symbols) of recombinant human IL-7.N13B2 is more efficient in inhibiting STAT 5 than MD707-13 (˜50%inhibition at 100 ng/ml for N13B2, vs. 1000 ng/mL for MD707-13), whiledifferent IgG isotypes of N13B2 display comparable inhibitionefficiency.

FIG. 3 . (A) Binding studies of rat N13B2 anti-CD127 antibody. N13B2antibody or MD707-1 were injected on a CD127 immobilized antigen atdifferent concentration. Resp. diff: Response difference. Time: time insec (total duration: 20 min). Blk: blank (no antibody). The associationand dissociation curves were analyzed with model “Bivalent analyte” onBIAeval 4 software. Results are presented in the Table 1 below.

TABLE 1 Results of bindng studies Ka (1/Ms) Kd (1/s) KA (1/M) KD (M)MD707-1 2.66 E+05 1.21E−04 2.19E+09 4.56E−10 N13B2  2.01E+05 1.60E−051.26E+10 7.96E−11

TABLE 2 Kd of N13B2 and its chimeras described in (A) in a separateexperiment Ka1 Kd1 Rmax KA KD Antibody (1/Ms) (1/s) (RU) (1/M) (M) N13B2rat 9.63E+04 4.75E−06 115 2.03E+10 4.93E−11 N13B2-G1 1.49E+05 5.62E−05109 2.65E+09 3.77E−10 N13B2-G4 2.01E+04 3.41E−06 94.9 5.89E+09 1.70E−10

FIG. 4 . The Anti CD127 activity of the new antibody N13B2 was measuredby ELISA assay using a recombinant hCD127 antigen. OD 450 nm: opticaldensity at 450 nm. A. The CD127 binding activity of the N13B2 (fullcircle) was compared to the previous antibody generation (MD707-1 (emptydiamond), 3 (empty triangle) and 6 (full square)). N13B2 appears as themost efficient binder in the assay. B. The CD127 activity betweendifferent N13B2 formats (rat, IgG1 (circle) or IgG4 (square)) wascompared. No significant difference in binding activity was observed.

TABLE 3 ED50 of selected antbibodies ED 50 (ng/ml) N13B2 65.64 MD707-1122.93 MD707-3 293.32 MD707-6 2789.41 St cMD707-3-G1 16.1 CN13B2-G1 12CN13B2-G4 12.6

FIG. 5 . TSLP-induced TARC (Thymus and Activation-Regulated Chemokine,CCL17) production and expression of CD80 cell surface marker by myeloiddendritic cells. None: no stimulation. LPS: stimulation withlipopolysaccharide. TSLP: stimulation with TSLP. A) Quantification ofTARC production in supernatant by ELISA and B) CD80 cell surfaceexpression by flow cytometry of human blood CD1C+ dendritic cellscultured for 24 hours with medium alone, 1 μg/ml LPS or 15 ng/ml ofTSLP. Data are mean±Standard error or the mean (SEM) concentration from3 independent experiments.

FIG. 6 . Inhibition of TSLP-induced TARC production by anti-human CD127antibodies. Quantification by ELISA of TARC production in supernatant ofhuman blood CD1C+ dendritic cells cultured for 24 hours with 15 ng/ml ofTSLP and different concentration of anti-human CD127 antibodies: N13B2antibody (circle), MD707-6 (triangle) and anti-TSLP as a control (X).Data are representative of three independent experiments from threedifferent blood donors. N13B2 inhibits only very moderately theinduction of TARC secretion (˜20% inhibition at 6 μg/mL), while MD707-13and anti-TSLPR are more efficient inhibitors (resp. ˜50% and ˜70%inhibition).

FIG. 7 . Effect of anti-CD127 antibodies on TSLP-induced CD80 and CD40expression marker of dendritic cells maturation. Cells were activated byTSLP at 15 ng/ml for 24 hours. N13B2, MD707-3 and MD707-6 anti-CD127antibodies were added to the supernatant at 6 μg/ml. CD80 (A) and CD40(B) expression at the cell surface were analysed by FACS. Data arerepresentative of 3 independent experiments and are expressed in % ofexpression in control cells (medium=no antibody, with TSLP). Only N13B2,of the tested antibodies, does not increase the cell surface expressionof CD40 and CD80 in TSLP-treated cells.

FIG. 8 . Antibody-dependent cellular cytotoxicity (ADCC) of chimericN13B2 (IgG1 or igG4) anti-human CD127 antibody. Human NK cells used aseffector (E) were incubated for 4 hours with a human CD127-transfectedBAF/3 cell line as target cells (10 effector to 1 target cell ratio) andwith different concentration of chimeric N13B2 IgG1 (full square),N13B-IgG4 (empty square) or chimeric MD707-3 (X). Percentage of specificcytotoxicity was determined by 51Cr release.

FIG. 9 . Efficacy of rat N13B2 anti-CD127 mAbs to improve colitisinduced chemically in humanized immunodeficient mice. Survival (A) andchange in weight (B) were monitored daily from day 0, start of thechemical treatment with 2,4,6-trinitrobenzenesulfonic acid (TNBS), whichinduces severe colonic inflammation when administered intrarectally,after injection of PBS (solid line/full triangle) or N13B2 anti-IL7Rαantibody (dotted line, empty triangle). In (B), each point represents anaverage weight data (+/−SEM); n=6 for the Hu-TNBS+PBS group and n=6 forTNBS group+anti-IL-7Rα. Survival is increased and weight loss is reducedin the treated group.

FIG. 10 . Nucleotidic and amino acid sequence of the N13B2_G1M chimeraVH and VL chains. Fc chains are printed in lower case, the three CDRs ineach sequence are underlined. An asterisk (*) designates the stop codonin the amino acid sequence.

FIG. 11 . Nucleotidic and amino acid sequence of the N13B2_G4M chimera.Fc chains are printed in lower case, the three CDRs in each sequence areunderlined. An asterisk (*) designates the location of the stop codon inthe amino acid sequence.

FIG. 12 . Amino acid sequence of three alternative human Fc chains(IgG1, IgG2 and IgG4) and of the Fc chain of the rat N13B2 antibody(IgG1).

FIG. 13 . anti-CD127 ELISA binding assay: coating human CD127Fc andrevealed with an anti-human kappa antibody. The Anti CD127 activity ofthe new antibody N13B2 was measured by ELISA assay using a recombinanthCD127 antigen. The CD127 activity between different N13B2 antibodyformats (wt (X), an IgG4 humanized h1 (full square), h2 (empty circle)or h3 (full triangle) antibodies) were compared. OD: optical density.

TABLE 4 ED 50 of selected antibodies ED 50 (ng/ml) N13B2 wt 3 N13B2-h12.4 N13B2-h2 0.6 N13B2-h3 0.6

FIG. 14 . FIG. 14 : P-STAT5 inhibition with anti-CD127 antibodies: A.Inhibition of IL7 induced P-STAT5 by humanized N13B2 mAbs on Tlymphocyte (N13B2 h1 (black square), h2 (open circle) and h3 (blacktriangle) in a dose dependent manner and compared to Rat N13B2 wt (X)antibody in the presence of 0.1 ng/ml of recombinant human IL-7. B.Different anti-CD127 antibodies from previous antibody generations werecompared for their ability to inhibit IL7 dependent P-STAT5: MD707 3(circle), MD707 4 (triangle) and MD707 13 (square).

TABLE 5 IC 50 of selected antibodies IC 50 (ng/ml) N13B2 wt 50.2N13B2-h1 63.8 N13B2-h2 18.7 N13B2-h3 21.2

FIG. 15 . Stability assay of humanized versus Rat anti-CD127 antibodies.Antibody concentrations was measured by ELISA after 7 days at 37° C.(Rat N13B2 wt (+) or humanized N13B2 h3 (square)) and at −80° C. (RatN13B2 wt (X) or humanized N13B2 h3 (triangle)) and after fourfrost/defrost events (diamonds).

TABLE 6 Binding activity of the antibodies after 7 days at 37° C. or at−80° C. and after 4 time frost/defrost events. ED 50 (ng/ml) N13B2wt_store at −80° C. 3.6 N13B2 wt_store 7 d at 37° C. 3.5 N13B2-h3_storeat −80° C. 1.3 N13B2-h3_store 7 d at 37° C. 1.1 N13B2-h3_4x frost anddefrost 1.7

TABLE 7 Stability assay of humanized versus rat anti- human CD127antibodies: Analysis by gel filtration of aggregate formation afterincubation for 7 days at 37° C. or at −80° C. N13B2-wt N13B2-h” D7 D7 D7D7 at −80° C. at 37° C. at −80° C. at 37° C. % aggregates  3  4 2.8 3.2% monomers 97 96 97.2 96.8

FIG. 16 . Competition and internalization assays by cytometry. Humanperipheral blood mononuclear cells were incubated with severalanti-CD127 mAbs, for 30 min at either 4° C. (hatched bar) or 37° C.(black bar) or at 37° C. for 30 min without IL-7 and then for 15 minwith 5 ng/ml of recombinant human IL-7 (grey bar): (A) 10 μg of clonesMD707-5, MD707-12 or MD707-13 or the chimeric N13B2-G4; (B) 50 ng ofN13B2, HAL clone H3L4 or 1A11 or medium as control. Cells were thenstained at 4° C. with commercially available anti-human CD127 mAbs toassess IL-7 receptor alpha chain expression at the cell membrane level.

MD707-5, MD707-12 and MD707-13 antibodies induced internalization of thereceptor at 37° C. with or without IL-7, while the chimeric N13B2-G4 didnot. HAL antibody induced a decrease in cell surface expression of CD127in any conditions. Results at 4° C. show that 1A11 antibody competesslightly with the antibody used for labelling, while HAL shows strongcompetition and N13B2 no competition. At 37° C., no cell surfacestaining was observed in the presence of HAL, while 1A11 alone induced astrong decrease in cell surface expression of CD127 and when combinedwith IL-7, the cell surface expression was decreased by ˜90%. Incontrast, N13B2 did not reduce cell surface expression of CD127 at 4°C., neither did it induce a decrease in cell surface expression of CD127used alone, and it inhibited the decrease observed in the presence ofIL-7.

FIG. 17 . (A) Pharmacokinetic and pharmacodynamics study of N13B2 andMD707-13 mAb administration in non-human primates. Baboons (Papioanubis) were treated intravenously with 10 mg/kg of N13B2-IgG1 (n=3,full square), N13B2-IgG4 (n=3, full circle) or MD707-13-IgG4 (n=3, emptycircle). Serum concentration of anti-CD127 mAb were monitored by ELISA.(B) In parallel, expression of CD127 at the surface of blood Tlymphocytes was monitored by flow cytometry and normalized to levelmeasured before injection of mAb (represented by dotted line). *p<0.05.Total plasma levels are comparable over time for all three antibodies.Cell surface expression of CD127 is decreased after ˜8 days of treatmentwith MD707-13, while no such decrease is observed with any of the testedN13B2 clones.

FIG. 18 . Baboons (Papio anubis) were treated intravenously with 10mg/kg of N13B2-IgG1 (n=3, full square), N13B2-IgG4 (n=3, full circle) orMD707-13-IgG4 (n=3, empty circle). The frequency of regulatory Tlymphocytes (CD3+ CD4+ CD25high Foxp3+) in blood and lymph nodes(expressed as % of CD4 positive T cells) as well as absolute countnumber of regulatory T lymphocytes (expressed in cells/mL) was monitoredat day 0 and 2 weeks after administration of mAbs. **p<0.01, ***p<0.001.All three antibodies increase the total count in blood and ratio in bothblood and lymph nodes of regulatory T cells.

FIG. 19 . In vitro inhibition of α4, β7 and α4/β7 integrin expression.A. Percentage of α4-positive and α4/β7-positive human T-lymphocyte,after 9 days of culture with or without 5 ng/ml of human IL-7, assayedby FACS. B. Same as top, with the indicated concentration of N13B2 mAbadded to the culture at day 0. Dotted lines indicated the baseline levelin a control condition (without IL-7 and N13B2 mAb). The IL-7-inducedincrease in expression of the α4, β7 and α4/β7 integrins is prevented byhumanized N13B2 mAb in-vitro (it is completely inhibited at ˜2 μg/mLantibody).

FIG. 20 . In vivo inhibition of α4, β7 and α4/β7 integrin expression.40×10⁶ human peripheral blood mononuclears cells were injectedintraperitonealy in irradiated immunodeficient mice (NOD/SCID/IL-2receptor gamma-chain knock-out mice). Percentage of blood β7-positive Tlymphocytes (left) and engraftment of β7-positive human T lymphocytes(right) after two weeks of treatment with control buffer (n=5) or N13B2mAb (5 mg/kg, n=5), assessed by FACS. **p<0.01. N13B2 significantlyreduces the ratio of β7 positive T cells, and the engraftment ofβ7-positive T cells.

FIG. 21 . Effect of N13B2 antibody on a DTH model, an in vivo psoriasismodel. BCG-(Bacillus Calmette-Guerin) vaccinated baboons (Papio anubis)were challenged by an intradermal injection of 2000 (A) or 1000 (B) unitof purified tuberculin to induce delayed-type hypersensitivity responseand diameters of erythema were recorded every day (asterisk; dottedline). One month later, animals were treated intravenously with 10 mg/kgof N13B2-IgG1 (n=3, full square), N13B2-IgG4 (n=3, full circle) orMD707-13-IgG4 (n=3, empty circle). Four hours after mAbs administration,animals were challenged again by an intradermal injection of 2000 (A) or1000 (B) unit of purified tuberculin to induce delayed-typehypersensitivity response and diameters of erythema were recorded everyday (solid lines). N13B2 but not MD707-13 antibody, inhibits memorylymphocytes response, as measured by the diameter of the erythema afterthe second challenge.

FIG. 22 . Baboons (Papio anubis) were treated intravenously with 10mg/kg of N13B2-IgG1 (n=3, full square), N13B2-IgG4 (n=3, full circle) orMD707-13-IgG4 (n=3, empty circle) or control buffer (n=3, dotted line).Four hours later, animals received an intravenous injection of 1.5 ml ofsheep red blood cells (SRBC) at 10%. Specific anti-SRBC IgG titers weremonitored 1 week and 2 weeks after administration of SRBC and normalizedto their titers at day 0. *p<0.05. N13B2, but not MD707-13, inhibitshumoral immune response, as measured by the specific IgG titer.

FIG. 23 . Protein sequence of the humanized N13B2 VH IgG4 S228P_h3:sequence in grey are the CDRs, underlined and bolded amino acids aremutated (V42I, A54S, D82N, M108L), underlined sequence is the mutatedIgG4 sequence (S228P).

FIG. 24 . Protein sequence of the humanized N13B2 VL Ckappa_h3: sequencein grey are the CDRs, underlined and bolded amino acids are mutated(V54I, Y77F, F93Y+N31Q, S59T), underlined sequence is the mutated IgG4sequence (S228P).

FIG. 25 . N13B2 protects from death in an Inflammatory mice model: agraft-versus-host-disease was induced in humanized mice (see Example13). Percentage of surviving NSG mice injected with 50 million humanPBMC on day 0 receiving no treatment (white square, n=14) or treatedthree times per week by intraperitoneal injection with 5 mg/kg ofchimeric N13B2 (black circle, n=19).

FIG. 26 . N13B2 specifically prevents colon inflammation in aninflammatory mice model (see Example 13). At time of euthanasia (i.e. at25% weight loss or 100 days after injection), inflammatory cellinfiltrates in each tissue of NSG mice injected with 50 million humanPBMC on day 0 and treated (black) or not (white) three times per weekwith 5 mg/kg of N13B2, was analyzed by histology on 10 μm slides stainedwith hematoxilin and eosin. Results are presented as follows: A. Colon,B. Intestine, C. Liver and D. Lung. Data are mean+/−SEM of at least n=8per group.

FIG. 27 . Epitope domains on CD127 protein (Uniprot P16871) that arerecognized by N13B2 antibody. Amino acids in bold font correspond to thesequences forming the conformational epitope recognized by N13B2; aminoacids on grey background are important for interaction with IL-7; aminoacids that are stricken-through constitute the signal peptide of CD127.

FIG. 28 . Co-immunoprecipitation study of the CD127/IL7/CD132 complexwith anti-hCD127 antibodies (Example 21). Lanes: 1—PBL alone, 2—PBL+IL7,3—PBL+IL7+N13B2, 4—PBL+IL7+MD707-13, 5—CD132-Fc (72 Kda) or CD-127-Fc(80 KDa). Co-immunoprecipitation of samples on anti-hCD127 column(MD707-9). Eluates were analysed by western-blot with (A) Rabbitanti-human CD132 antibody revealed with peroxidase-labelled goatanti-rabbit or with (B) Rat anti-human CD127 antibody and revealed witha peroxidase-labelled donkey anti-rat antibody.

EXAMPLES Example 1. Preparation and Selection of Novel Anti-Human CD127Mabs

Rats were immunized with recombinant hCD127-Ig (hCD127 fused with aconstant fragment of an immunoglobulin—Sino Biologicals, Beijing, China;reference 10975-H03H) and monoclonal antibodies were derived accordingto conventional techniques. The immunization protocol used was asfollows: recombinant CD127 Fc Chimera (10975-H03H Sino Biological,Beijing, China) was used to immunize rats of the LOU/C Igk1a strain.Fifty micrograms of proteins were suspended in Complete Freund Adjuvantand administered s.c. After 20 days, a recall injection of the proteinsuspended in Incomplete Freund Adjuvant was performed. Another similarrecall injection was performed on days 60 and a boost injection wasperformed on day 90 with 100 micrograms proteins, 4 days before spleencells collection.

Hybridoma were obtained by fusing spleen mononuclear cells with the LOUrat immunocytoma IR983F, a non-secreting and azaguanine resistant cellline, according to a previously described procedure (Chassoux et al,1988). Hybridoma were first screened according to the capacity of thesecreted monoclonal antibodies to bind to recombinant CD127 molecule(CD127 Fc Chimera; 10975-H03H, Sino Biological, Beijing, China).

After selection, hybridoma were cultured in DMEM complete medium.Supernatant was concentrated by ultrafiltrafiltration (Centramate, Pall)and purified by affinity on Protein G chromatography (HiTrap,GeHealthcare). Elution was performed with glycine 0.1M pH 2.8 elutionbuffer. Resulting purified immunoglobulins were assessed in activityELISA assay against CD127 human.

Among the first selected clones selected based on the recognition bysecreted antibodies of recombinant CD127, 2 were further selected byflow cytometry on the recognition of CD127 expressed by human T cellsand on their antagonist properties with respect to TSLP.

Antibodies were produced and their isotype were characterized as well astheir affinities by Surface Plasmon Resonance measurement using BIAcoretechnology.

Example 2. rCD127 Recognition of Anti-h-CD127 Mabs Assessed by ELISA

Recombinant hCD127 (Sino Biologicals, Beijing, China; reference10975-H08H) was immobilized on plastic and increasing doses of Mabs wereadded to measure binding. After incubation and washing,peroxidase-labeled mouse anti-rat kappa chain (AbdSerotec) was added andrevealed by conventional methods. Binding was confirmed for eachantibody.

Example 3. Inhibition of IL7 Signaling (pSTAT5)

Human peripheral blood monocytic cells (PBMC) harvested by ficollgradient from healthy volunteers were incubated in serum-free media withdifferent concentration of antibodies of interest for 15 minutes at roomtemperature, before incubation with 0.1 or 5 ng/ml of recombinant humanIL-7 (rhIL-7; AbD Serotec ref PHP046) for 15 minutes at 37° C. PBMCuntreated with rhIL-7 were analyzed as the background signal, while IL-7treated cells without antibody were set as negative control. PBMC werethen quickly chilled and washed with FACS buffer to stop the reaction.Cells were then incubated for 15 minutes with cold Cytofix/Cytopermsolution (BD Bioscience, ref 554722), washed twice with Perm/Wash buffer(Bd Bioscience) and stained with an anti-human CD3 FITC antibody (BdBioscience ref 557694) for 30 minutes on ice. PBMC were then washedtwice with Perm/Wash buffer and permeabilized in BD Perm Buffer Ill (BdBioscience, ref 558050) for 30 minutes. Cells were then washed twice inFACS buffer (and/or PBS with 1% BSA and 0.1% azide) and incubated for 30minutes at room temperature with anti-human pSTAT5 Alexa 647 antibody(BD Bioscience, ref 612599). Samples were analyzed on BD CANTO II FACSinstrument. As shown in FIG. 1 and FIG. 2 , N13B2 and chimericantibodies derived therefrom (N13B2-G1 and N13B2-G4) are stronginhibitors of STAT5 phosphorylation; with more than 50% inhibition atconcentrations as low as 50 ng/ml and more than 80% (for 0.1 ng/ml ofIL-7) or more than 90% (for 5 ng/ml of IL-7) inhibition at antibodyconcentrations as low as 100 ng/ml.

Example 4. Half-Inhibitory Concentration (IC50) of Different Anti-HumanIL-7Rα Monoclonal Antibodies are Displayed in Table 1

TABLE 8 IC50 of different anti-CD127 antibodies on P-STAT5 induced by100 pg/ml of rhIL 7 IC50 N13B2 N13E5 N13K12 MD707-3 N13B2-G1 N13B2-G4pg/ml 43 50 62 1090 28 37

Example 5. IL7R Internalization Assay by Cytofluorometry

The internalization assay could be performed using a confocal microscopeas detailed in the material and method of Henriques et al (2010) and Luoet al. (2011). To observe the internalization of the CD127 in theabsence of IL-7, antibodies hN13B2, HAL clone H3L4 (U.S. Pat. No.8,637,27) or 1A11 (international patent application WO2011094259) at afinal concentration of 50 ng/ml (or antibodies MD707-5, MD707-12,MD707-13 or N13B2-G4 at a final concentration of 10 μg/ml, wereincubated with human PBMC (100000 cells/well) in serum-free medium(TexMACS, Miltenyi Biotec) for 30 min at 4° C. or 37° C. To observe theinternalization of the CD127 in the absence of IL-7, the samepre-incubation conditions were used at 37° C. with antibodies and cellswere then stimulated with recombinant IL7 (AbD Serotec, ref PHP046) at0.1 ng/ml for 15 min at 37° C. The reaction was stopped at 4° C., andthe cells were washed 3 times with PBS-1% BSA-0.1% azide before stainingwith PE-labelled anti-CD127 (clone hIL7R-M21, BD Bioscience, ref 557938)diluted at 1/10 in PBS-1% BSA-0.1% azide and incubated 15 min at 4° C.After washing, cells were analysed by cytofluorometry with Cantollcytometer (BD Biosciences). Results presented in FIG. 16 arerepresentative of three independent experiments.

This method is readily adaptable in 96 well plates in order to perform ascreening and to select antibodies that block the IL7-dependent or-independent CD127 internalization.

Example 6. Anti-CD127 Antibody Affinity Study

The affinity of the anti hCD127 antibody was measured by surface plasmonresonance on a Biacore 3000 (GE Healthcare)

A CM5 chip (GE healthcare) was activated by injection of NHS/EDC mix for7 min. The CD-127Fc (500 μg/mL) was diluted in 5 mM maleate buffer pH6.2was injected and the succinimide ester residues until a hooking 300RUsignal. The free reactive residues were inactivated by the injection of1M ethanolamine pH8.5. Antibodies were injected over the immobilized CD127 in the concentration range specified in the results section. Theinjection rate was set at 40 μL/min, the association was measured for 3min and dissociation for 10 min. Between each cycle of the analysis, thechip was regenerated by injection of a solution of 5M MgCl2 for 60 s.

The obtained sensorgrams were analyzed with model “Bivalent analyte” onBIAeval 4 software.

As shown in FIG. 3 and Table 2 therein, the N13B2 from rat andchimerized displayed a high affinity for CD127, with a KD in the range4.9E-11 M-8.E-11 M (N13B2 from rat), 3.77.E-10 (N13B2-G1) and 1.70.E-10(N13B2-G4). MD707-1 antibody from rat showed a lower affinity to CD127than the N13B2 from rat.

Example 7. Anti-CD127 Antibody Binding Activity

For sandwich ELISA, donkey anti-human IgG (Fc specific) antibody wascoated at 1.2 μg/ml on P96-plate and purified antibodies were added tomeasure concentration in function of standard range. After incubationand washing, mouse anti-human light chain, kappa specific, (Abcam,reference ab79115 or Effimune, clone NaM76-5F3) plus peroxidase-labeleddonkey anti-mouse (Jackson Immunoresearch, reference 715-036-151)antibodies were added and revealed by conventional methods.

The binding activity of the anti hCD127 antibody was assessed by ELISA(Enzyme-linked immunosorbent assay). For the ELISA assay, recombinanthCD127 (Sino Biologicals, Beijing, China; reference 10975-H08H) wasimmobilized on plastic at 1 μg/ml and purified antibody were added tomeasure binding. After incubation and washing, peroxidase-labeled mouseanti-rat kappa chain (AbdSerotec) was added and revealed by conventionalmethods.

As shown in FIG. 4 and Table 3, the binding activity as measured byELISA of the N13B2 antibody is high, with an ED50=65.6 ng/mL (ED50<75ng/ml and ED50<100 ng/ml) for the rat N13B2 anti-hCD127 antibody and anED50 of 12.0 ng/ml and 12.6 ng/ml (ED50<15 ng/ml) for two chimericantibodies derived from N13B2 (cN13B2-G1 and cN13B2-G4).

Example 8. Stability Assay

Humanized and chimeric purified N13B2-G1 were incubated at 37° C. or at−80° C. for 7 days. Two assays were used to measure stability ofantibody: binding anti-CD127 by ELISA assay, and aggregate formation bygel filtration. For activity ELISA assay, recombinant hCD127 (SinoBiologicals, Beijing, China; reference 10975-H08H) was immobilized onplastic at 1 μg/ml and dilutions of supernatant were added to measurebinding. After incubation and washing, mouse anti-human light chain(kappa specific) plus peroxidase-labeled donkey anti-mouse antibodieswere added and revealed by conventional methods. For analysis ofaggregate formation, sample was analysed on gel filtrationchromatography column (Superdex 200, 10/300GL, GeHealthcare) to separateand evaluate aggregate and monomer from samples.

Example 9. TSLP-Induced Production of TARC and Expression of the MaturedDendritic Cell Markers CD80 and CD40

Myeloid dendritic cells (DC) were isolated with CD1c (BDCA-1)+ Dendriticcell isolation kit (Miltenyi Biotec, Bergisch Gladbach, Germany) fromblood of healthy volunteers (Etablissement Français du Sang, Nantes,France). Myeloid dendritic cells were cultured in RPMI containing 10%fetal calf serum, 1% pyruvate, 1% Hepes, 1% L-glutamine and 1%penicillin-streptomycin. Cells were seeded at 5.104 cells/well inflat-96-well plates, in the presence of TSLP (15 ng/ml), LPS (1 μg/ml)or culture medium alone, and addition of rat anti-human CD127 antibodiesat different concentrations. At 24 hours of culture, cells were analyzedby flow cytometry for CD80 cell surface marker of maturation(anti-CD80-V450 (BD #560442) and supernatants were collected andanalyzed for TARC production by ELISA assay (R&D systems, Minneapolis,USA).

The inhibition of TSLP-induced production of TARC was assessed bymeasuring said production as described above in the absence of antibodyor in the presence of N13B2 or MD707-6 or commercial anti-TSLPR antibody(R&D systems ref. AF981) at 1 μg/ml or 6 μg/ml. As shown in FIG. 6 ,N13B2 inhibited TSLP-induced TARC production by more than 25% atconcentrations as low as 1 μg/mL, i.e. as efficiently as MD707-6 at thisconcentration.

The inhibition of TSLP-induced expression of CD40 and CD80 cell surfacemarkers were assessed by measuring said expression as described above(for CD40, antibody (anti-CD40-FITC from Beckton Dickinson ref. 555588)was used in similar conditions as those described above for CD80) in theabsence of antibody (expression normalized at 100% for this condition)or in the presence of N13B2, MD707-3 or MD707-6 antibodies at 6 μg/ml.As shown in FIG. 7 , both MD707-3 and MD707-6 induced an increase ofCD40 and CD80 expression, while MD707-3 is a good inhibitor of STAT5activation and a good binder of CD127 (FIG. 2 and FIG. 4 ) and MD707-6is a strong inhibitor of TSLP-induced production of TARC (FIG. 6 ). Theincrease was at least 20% for CD80 and 50% for CD40. In contrast, theantibody of the invention, N13B2, did not increase TSLP-inducedexpression of CD40 or CD80. Instead, said expressions were lower in thepresence of the TSLP and the antibody than in the presence of TSLPalone.

Example 10. Antibody-Dependent Cellular Cytotoxicity (ADCC) ofAnti-Human CD127 Mabs

ADCC refers to as the binding of an antibody to an epitope expressed ontarget cells and the subsequent Fc-dependent recruitment of effectorimmune cells expressing Fc receptors (essentially NK cells and activatedlymphocytes), resulting in the killing of target cells mainly bygranzyme/perforin-based mechanisms.

Effector cells were fresh primary human NK cells isolated fromperipheral blood mononuclear cells by negative selection using magneticbeads (NK isolation kit, Miltenyi Biotec, Bergisch Gladbach, Germany)and an AutoMACS cell sorting instrument. NK cells were incubatedover-night at 37° C., 5% CO2, in RPMI 1640 Medium (Life Technologies,Carlsbad, California) complemented with 10% FBS (Life Technologies), 100IU/ml penicillin (Life Technologies), 0.1 mg/ml streptomycin (LifeTechnologies), 2 mM L-glutamine (Life Technologies) and 150 IU/ml ofhuman IL-2 (Roche, Basel, Switzerland). The target cells (a humanCD127-transfected BAF/3 cell line (Park et al., 2000)) were labeled with100 μCi (3.7 MBq) of 51Cr (PerkinElmer) for 1 h at 37° C. and washedfive times with culture medium. Target cells were incubated with dilutedantibodies or with excipient (culture medium) for 15 min at roomtemperature and 10 000 cells were placed in a 96-well U-bottom plate.Effector T cells were added at a 10:1 cell ratio (final volume: 200 μl)for a 4 hours incubation period at 37° C. A total of 25 μl of thesupernatant was then harvested and counted in a gamma counter (PackardInstrument).

Both MD707-3 of rat origin and the chimeric N13B2-G1 (thus having anIgG1 type Fc domain) Mabs did elicit ADCC. The chimeric N13B2-G4 (havingan IgG4 type Fc domain) did not show any ADCC activity and was used as anegative control. Interestingly, there is no direct correlation betweenaffinity, binding and ADCC properties, indicating that ADCC propertiescould not be predicted from binding analyses.

Example 11. Nucleotides and Amino Acid Sequences of Anti-Human CD127Mabs

VH and VL regions of the N13B2 clone were sequenced using the RACE PCRtechnology. Briefly, total RNA was extracted, reverse transcribed andthe resulting cDNA was poly-adenylated at the 3′ end of the moleculesusing dATP and the terminal transferase enzyme. A first 35-cycle PCRreaction was performed using an oligodT anchor primer and Herculeaseenzyme (Stratagene). A second 35-cycle PCR was performed using nestedPCR anchor primers. The resulting PCR product was then TA-cloned in E.coli and after selection on ampicillin, resulting colonies were screenedby restriction enzyme profiling and inserted cDNA sequenced.

Example 12. Humanization

The humanization of rat N13B2 monoclonal antibody was accomplished usingthe standard CDR-grafting technology. The principle of this method is toreshape a human antibody so that it contains only the complementaritydetermining regions (CDRs) from the rat monoclonal antibody aiming tonot only reduce antibody immunogenicity in humans but also improvedbiophysical properties of the CDR-grafted molecule.

Humanization by CDR-grafting requires that the antigen-binding residuesfrom the parental rat antibody are retained in the humanized version.Residues adjacent to CDRs, termed “Vernier” residues, were found toaffect CDR conformations and to fine-tune antigen recognition. Chothiaand Lesk, (1987) segregated CDR conformations according to “canonical”residues, some of which are located within the CDRs themselves, othersin the framework regions. The identification of these “Vernier” and“canonical” residues is therefore a critical step. The protocol used isbased on the approach pioneered by Greg Winter and colleagues (Paus andWinter, 2006) at the Medical Research Council, Cambridge, UK and usesKabat-defined CDR-residues.

The selection of human framework acceptor regions onto which the ratN13B2 CDR regions are grafted was accomplished by searching the IMGT ratand human V genes database using IgBLAST—a tool developed at NCBI tofacilitate analysis of immunoglobulin variable region sequences(http://www.ncbi.nlm.nih.gov/igblast; Ye et al., 2013) with the ratN13B2 VH and VL sequences as input. Besides, the strategy here applieduses human germline sequences which are natural human sequences notcontaining the somatic hypermutations found in the protein andcDNA-derived sequences. Germline genes most similar to the rat VL and VHsequences were usually selected. Human germline framework acceptor VHand VL regions were identified by parental N13B2 VH and VL antibodysequences alignment and based on the following criteria: 1.

Sequence identity across the framework and CDRs as defined by Kabat, 2.Identical and compatible inter-chain interface residues, 3. Supportloops with the parental CDR canonical conformations and Vernierresidues.

A few different sequences of humanization were tested for N13B2 tochoose the best one, which maintains binding and biological activity.For humanization variants of N13B2, variable sequence of humanized heavychain (VH) of N13B2 antibody was cloned by EcoRV in pFuseCHIg-hG1e4expression plasmid (Invivogen, Toulouse) containing CH1-CH2-CH3 domainsof hIgG1, mutated at E333A to increase ADCC. The variable sequence ofthe humanized light chain (VL) of N13B2 antibody was cloned by BsiWI inpFuse2CLIg-hk expression plasmid (Invivogen, Toulouse) containing humanCLkappa.

In COS cells, we have co-transfected, by lipofectamine method, plasmidcontaining VH-hFcG1 with plasmid containing VL-CLk. After 48-72 hincubation, supernatant was recovered and purified by affinity onProtein G chromatography (HiTrap, GeHealthcare) with glycine 0.1M pH 2.8elution buffer. Purified antibody was dialyzed in PBS and concentrated.They were quantified by sandwich ELISA and tested in activity assayagainst CD127 antigen.

Example 13. Study of Anti-IL7Rα Antibodies on IL-7 on Different In VivoInflammatory Disease Models

With the aim to examine the effect of an antagonist antibody in theinduction of colitis in humanized NSG mice, we conducted a series ofexperiments in the TNBS model, which have shown a measurable effect. Theuse of haptens such as the TNBS (2, 4, 6, trinitrobenzene sulfonic acid)allows to induce an immunological model mimicking (Nancey et al., 2008).Colitis is induced in mice by intrarectal administration of TNBS (SigmaChemical, L'Isle d'Abeau Chesne, France) dissolved in ethanol at day 0in four humanized mice. Initially, the mice are anesthetized byinhalation of a gas mixture. On day 7, the animals were sacrificed underanesthesia by CO2 intoxication for several studies (data not shown).Some animals were sacrificed before day 7 because of their bad clinicalscore.

Two new groups of mice were therefore treated with either PBS or withinjections of 210 μL at 0.7 mg/mL of an N13B2 anti-IL7Rα every 2 daysstarting the day before TNBS treatment. Similar analyses were performedto those made in the development of the model.

We then tested N13B2 antibody efficacy in a humanized graft-versus-hostdisease (GVHD) mice model. This model mimics a global inflammatorydisease. Some 7 to 12 weeks old NOD/scid/IL-2Rγ−/− (NSG) mice (CharlesRiver, L'arbresle, France) were irradiated (3Gy) and infusedintraperitonealy (i.p.). with 50 million human PBMC from healthy donorsas described previously by Poirier et al., 2012. Animals were thenmaintained in aseptic conditions and were monitored three time per weekfor weight evolution and clinical evaluation. A control group was leftuntreated after infusion of cells and a treatment group received, fromday 0 and three times per week, i.p injections of 5 mg/Kg of chimericN13B2 mAb. GVHD diagnosis was given to a mouse upon a 20% weight loss.Animals found to have more than 25% weight loss, and animals survivingafter 100 days from day 0 were euthanized. After euthanasia, colon,intestine, liver and lung tissues were frozen in liquid nitrogen andTissu-tek for histological analysis. Frozen sections (10 μm) from thesetissues were air dried at room temperature for 1 h before acetonefixation for 10 min at room temperature and then stained withhematoxylin and eosin solution. Results are presented in FIG. 25 andFIG. 26 .

Example 14. Analysis of Various Clinical Parameters

Survival (FIG. 9A): we assessed the survival rate according to thechemical treatment and the use of the anti-IL7Rα antibody. Thepercentage of survival tends to be more important for the Hu-TNBS+IL7Rαgroup than for Hu-TNBS+PBS group (FIG. 9A). Indeed, we observed that100% of the mice of Hu-TNBS group+IL7Rα survive up to 5 days while inthe Hu-TNBS+PBS group, three animals had to be euthanized before J5.

Weight (FIG. 9B): in the TNBS treated groups from day 0 of the intrarectal injection of 5% TNBS/ethanol 50%, we observed a decrease inweight up to 20% for both groups. However, in the Hu-TNBS+IL7Rα group,the animals gained weight from J3 while in the Hu-TNBS+PBS group, weightloss continued (FIG. 9B). It is important to note that the mice had tobe sacrificed to collect biological data and a protocol in the longerterm would confirm the weight regain.

Survival (FIG. 25 ): we assessed the survival rate according toinjection of human PBMC (GvHD development) and the use of the anti-IL7Rαantibody N13B2. The rate of surviving animals is 30% better when animalsare treated with antibody than in control animals (100% death rate ofcontrol animals after 60 days). This results shows that the N13B2antibody protects against GvHD and death.

Tissues infiltrate (FIG. 26 ): colon, intestine, liver and lung fromdead and surviving animals (but euthanized) treated or not werehistologically analyzed for their inflammatory cell infiltrate rate(histological score was determined). We observed that the colon of theanimal treated with N13B2 contained less cell infiltrate than thecontrol. No difference was observed in intestine, liver and lung betweenboth conditions.

Animals treated with the N13B2 showed 30% survival rate compared to thecontrol. The cell infiltrate characterizing the inflammation isunmodified by the treatment in the intestine, liver and lung tissuesshowing that in this model of inflammation the N13B2 does not protectagainst the inflammation in these tissues. However, N13B2 induced a 50%decrease of the cell infiltrate in colon. This effect could becorrelated with the activity of the N13B2 antibody on α4β7 integrinexpression as presented FIGS. 19 and 20 . Indeed, α4β7 integrin is knownto play an important role in homing of activated lymphocytes to the gut.So the decrease of the expression of the integrin induced by N13B2antibody may be responsible for the decrease of cell infiltrate observedin the colon (FIG. 26 ). It should be emphasized that the apparentabsence of protection in other tissues could be specific to the modelused here, and should not lead to the conclusion that the protectiveeffect of the antibody is limited to the colon. In particular, the muchhigher survival of treated animals shows that the protective effect ofthe antibody has a strong positive impact on the overall condition ofthe animals.

Example 15. In Vivo Efficiency of Non-Internalized CD127 AntibodyAnimals

Baboons (Papio anubis, from the CNRS Primatology Center, Rousset,France) were negative for all quarantine tests, including a tuberculinskin test. Animals were housed at the large animal facility of ourlaboratory following the recommendations of the Institutional EthicalGuidelines of the Institut National de la Santé Et de la RechercheMédicale, France. All experiments were performed under generalanaesthesia with Zoletil (Virbac, Carron, France). Pharmacokinetic andpharmacodynamic studies were performed during DTH experiments on fivebaboons receiving an i.v. bolus of either 10 mg/kg of N13B2-IgG1 orN13B2-IgG4 or MD707-13-IgG4.

BCG Vaccination and DTH Assay

According to Poirier et al, (Poirier et al., 2011), Baboons wereimmunized intradermally (i.d.) twice with a bacillus Calmette-Guérin(BCG) vaccine (0⋅1 ml; 2-8 ¥ 105 UFS; Sanofi Pasteur MSD, Lyon, France)in the upper region of the leg, 4 and 2 weeks before the DTH skin test.To investigate antigen-specific T cell immunity before DTH skin testing,successful immunization was confirmed by interferon (IFN)-genzyme-linked immunospot (ELISPOT) assay (non-human primate IFN-gELISPOT kit; R&D Systems, Minneapolis, MN, USA) on freshly isolatedPBMC, according to the manufacturer's instructions. Intradermalreactions (IDR) were performed with duplicate intradermal injections oftwo doses (1000 UI or 2000 UI) of tuberculin-purified protein derivative(PPD; Symbiotics Corporation, San Diego, CA, USA) in 0.1 ml in the skinon the right back of the animals. Saline (0.1 ml) was used as a negativecontrol. Dermal responses at the injection sites were measured using acaliper square. The diameter of each indurated erythema was measured bytwo observers from days 3-8, and were considered positive when >4 mm indiameter. The mean of the reading was recorded. Skin biopsies from theDTH or control (saline) site were performed at day 4 on one duplicateand placed in Tissue Tek optimal cutting temperature (OCT) compound(Sakura Finetek, Villeneuve d'Ascq, France) for immunohistochemicalanalysis. A second IDR was performed after a 3-week washout period andanimals received one i.v. injection of either 10 mg/kg of chimeric CD127antibodies (N13B2-IgG1 or N13B2-IgG4 or MD707-13-IgG4) 1 day before thissecond challenge with PPD. A third IDR was performed after a further3-6-week washout period and animals were left untreated. In some cases,a fourth IDR was performed after another 3-month washout period andanimals were also left untreated.

Example 16. α4β7 Expression at T Cell Surface In Vitro and In Vivo onMice Model

To measure IL7 induced α4β7 expression at the T cell surface, humanT-lymphocyte were stimulated for 9 days at 37° C., with IL7 (AbDSerotec, ref PHP046) at 5 ng/ml. Reaction was stopped a 4° C., andwashed before stained with PerCP/Cy5-labelled anti-α4 (BD Bioscience563644 clone 9F10) and PE-labelled anti-β7 (BD Bioscience, cloneFIB504). Positive cells for α4 integrin and then β7 positive cells weremeasured by flowcytometry. N13B2 humanized antibody was added at day 0to the cell culture at different concentration from 0.01 to 20 ug/ml

In-vivo, 40×10⁶ human peripheral blood mononuclears cells were injectedintraperitonealy in irradiated immunodeficient mice (NOD/SCID/IL-2receptor gamma-chain knock-out mice). Two weeks after treatment withcontrol buffer (n=5) or N13B2 mAb (5 mg/kg, n=5), the percentage ofβ7-positive T lymphocytes in the blood was measured by flow cytometryand engraftment of β7-positive human T lymphocytes was measured by flowcytometry. This engraftment was measured by flow cytometry bydiscriminating human CD45 positive cell from mouse CD45 positive cellsusing specific antibodies (PECy7 anti-humanCD45 from BD reference 57748and PerCPCy5.5 anti-mouse CD45 from BD reference 550994) then human 37positive cells were analysed (BD Bioscience, clone FIB504).

Example 17. Antibody Profiling Using Peptide Microarray

The peptide Technologies' PepStar™ peptide microarrays comprise purifiedsynthetic peptides derived from antigens or other sources that arechemoselectively and covalently immobilized on a glass surface. Anoptimized hydrophilic linker moiety is inserted between the glasssurface and the antigen-derived peptide sequence to avoid falsenegatives caused by sterical hindrance. For technical reasons allpeptides contain a C-terminal glycine. Profiling experiments of sampleswere performed on a peptide library consisting of 52 peptides. Thecomplete list of peptides is shown below:

TABLE 9 List of peptides used in peptide microarray assays SEQ SEQ SEQID Sequence ID Sequence ID Sequence 58 ESGYAQNGDLEDA 76 FIETKKFLLIGKSNI 94 HDVAYRQEKDENK EL WT 59 AQNGDLEDAELDD 77 KKFLLIGKSNICVKV  95YRQEKDENKWTHV YS NL 60 DLEDAELDDYSFS 78 LIGKSNICVKVGEK  96 KDENKWTHVNLSSCY S TK 61 AELDDYSFSCYSQ 79 SNICVKVGEKSLTC  97 KWTHVNLSSTKLTL LE K L 62DYSFSCYSQLEVN 80 VKVGEKSLTCKKID  98 VNLSSTKLTLLQRK GS L L 63SCYSQLEVNGSQH 81 EKSLTCKKIDLTTIV  99 STKLTLLQRKLQPA SL A 64QLEVNGSQHSLTC 82 TCKKIDLTTIVKPEA 100 TLLQRKLQPAAMYE AF I 65NGSQHSLTCAFED 83 IDLTTIVKPEAPFDL 101 RKLQPAAMYEIKVR PD S 66HSLTCAFEDPDVN 84 TIVKPEAPFDLSVIY 102 PAAMYEIKVRSIPD TT H 67CAFEDPDVNTTNL 85 PEAPFDLSVIYREG 103 YEIKVRSIPDHYFK EF A G 68DPDVNTTNLEFEIC 86 FDLSVIYREGANDF 104 VRSIPDHYFKGFWS G V E 69NTTNLEFEICGALV 87 VIYREGANDFVVTF 105 PDHYFKGFWSEWS E N PS 70LEFEICGALVEVKC 88 EGANDFVVTFNTS 106 FKGFWSEWSPSYY L HL FR 71ICGALVEVKCLNFR 89 DFVVTFNTSHLQKK 107 WSEWSPSYYFRTP K Y EI 72LVEVKCLNFRKLQ 90 TFNTSHLQKKYVKV 108 SPSYYFRTPEINNS EI L S 73KCLNFRKLQEIYFI 91 SHLQKKYVKVLMH 109 YFRTPEINNSSGEM E DV D 74FRKLQEIYFIETKKF 92 KKYVKVLMHDVAY RQ 75 QEIYFIETKKFLLIG 93 KVLMHDVAYRQEKDE

A total of 9 samples were incubated on microarray slides using aMultiwell-format. For N13B2 antibody and the other samples, 4 differentconcentrations were applied (10, 1, 0.1 et 0.01 μg/ml). One negativecontrol incubation (secondary antibody only) was performed in parallel.Human and mouse IgG proteins were co-immobilized alongside each set ofpeptides to serve as assay controls. All incubations were performed inparallel using two slides. Two peptide-mini-arrays on each slide wereused as a control incubation by applying the fluorescence labelleddetection antibody alone to assess false-positive binding to thepeptides. After washing and drying of the slides they were scanned witha high-resolution laser scanner at 635 nm to obtain images offluorescence intensities. The images were quantified to yield a meanpixel value for each peptide. Secondary antibody anti-rat IgG (JIR212-175-082) labeled with Cy5 at 1 μg/ml. Buffers and solutions Thebuffer used were TBS-buffer including 0.05% Tween20 (JPT) and Assaybuffer T20 (Pierce, SuperBlock TBS T20, #37536). Acquisition andanalysis were performed using Peptide microarrays (JPT PeptideTechnologies GmbH, Berlin, Germany; batch #2668, Multi-Well incubationchamber, Axon Genepix Scanner 4200AL, Spot-recognition software GenePixand Microsoft Excel, R

Example 18. Epitope Mapping by Mass Spectrometry Analysis

Mass spectrometry was used to identify a conformational epitope.Sequencing of the epitope was done using a MALDI mass spectrometer. Thisinstrument allows a peptide sequence between 800 and 4000 Da. Digestionof the protein of interest allows cutting the protein into smallfragments (potential epitopes). Ideally, the digestive enzyme must cutas close as possible to the borders of the epitope. Choosing thedigestion enzyme is to be made according to the enzyme cutoff frequencyin the sequence of the recombinant protein. A second digestion isconsidered to reduce the size of the epitopes obtained at the end of thefirst digestion. Depending on the selected enzyme, the profiles differsignificantly. The enzyme having the best distribution of digests on thesequence is chymotrypsin. A second enzyme with a proper cut-offfrequency and well distributed on the sequence of interest is Glu C.

Since the epitope is conformational, preference is given to thedigestion of the complex during affinity chromatography. Theidentification of the sequence of interest is based on the protection ofthe epitope against enzymatic digestion by the formation ofantigen-antibody complex. After passage through affinity chromatographyand digestion, the fragments of the epitope are eluted and sequenced bymass spectrometry (MALDI-TOF-TOF Bruker). The 3D structure of theprotein of interest is available and is compared to the resultsobtained.

Uniprot P16871 [21-239] (Seq ID No: 114): corresponds to the Topologicaldomain of the Homo sapiens Interleukin-7 receptor subunit alpha:

ESGYAQNGDLEDAELDDYSFSCYSQLEVNGSQHSLTCAFEDPDVNTTNLEFEICGALVEVKCLNFRKLQEIYFIETKKFLLIGKSNICVKVGEKSLTCKKIDLTTIVKPEAPFDLSVIYREGANDFVVTFNTSHLQKKYVKVLMHDVAYRQEKDENKWTHVNLSSTKLTLLQRKLQPAAMYEIKVRSIPDHYFKGFWSEWSPSYYFRTPEINNSSGEMD

In silico, CD127 digestion enzyme choices (see underlined amino acidsabove in the sequence corresponding to Seq ID No:114): Chymotrypsin waschosen as a digestion enzyme. The cutting sites (bold lines), thepeptide number, the frequency of the cuts are suitable. Glu-C enzyme waschosen as a second digestion enzyme. The number of peptides obtainedwith a weight comprised between 800 and 4000 Da is suitable. Thefrequency of Glu-C cuts and the location of cutting sites (thin line)are suitable. The procedure used is conventional and well-known to theskilled person and is described in Suckau et al, 1990 and Papac et al,1994.

Material and Reagents: Masse spectrometry MALDI-TOF/TOF II de Bruker;Hi-trap NHS columns (Ref: 17-0716-01-GE healthcare); Chymotrypsine (Ref:11418467001-Roche); Glu C (Ref: 11420399001-Roche); Zip/TIP C18 (Ref:ZTC18S096-Millipore); Ammonium bicarbonate (Ref: 09830-Sigma); Glycine(Ref: G7126-Sigma); NaCl (Ref: 27800.360-VWR).

Phase 1: Digestion of the free protein and antibody in solution.Digestion in solution of free antigen and antibody by chymotrypsin orGlu C for 1 h, 2 h, 3 h, 4 h, 5 h and overnight at room temperature or37° C. The analysis of the digested peptides was performed by Massspectrometric (MS) of the digested peptides. These experiments allow toestablish the suitable conditions of enzymatic digestions (time andtemperature). The aim is to have sufficient digestion of the antigen,while impacting the structure of the antibody as little as possible.Optimal conditions were determined to be: Chymotrypsin digestion: 1 hourat room temperature; Glu-C digestion: overnight at 37° C. Each digest ofthe antigen and antibody is analyzed by mass spectrometry MALDI-TOF/TOF.

Phase 2: Total digestion of the complex whole tied Ac+whole antigen. Thecoupling of the anti-CD127 monoclonal antibody N13B2-G1 (batch 210415)was performed on of Hi-Trap NHS column following the standard procedure.The antigen immunocapture on the column was performed during 1 h,allowing the formation of antigen-antibody complex. N13B2-G1 Antibodycoupling efficiency on the four columns Hi-Trap NHS ware as follows:84%, 84%, 83% and 83%. Consistent and identical coupling yields wereobtained.

Digesting the complex was performed in the ratio 1/50, or 1 mg of enzymefor 50 mg of antibody, at a temperature and for the duration determinedby the controls mentioned above. The column is then washed with the washbuffer (ammonium bicarbonate 25 mM) to remove and recover the unboundantigen peptides. A washing step in buffered saline (PBS-2M NaCl) isalso performed to remove nonspecific peptides. After washing, elution isperformed with an eluting solvent (50 mM Glycine pH 2) to specificallyextract and recover the specifically bound peptides (which are predictedto correspond to the epitope).

MALDI Analysis: washing and elution fractions are concentrated byhydrophobic chromatography on a C18 matrix. They are then analyzed bymass spectrometry MALDI-TOF/TOF. MS analysis can precisely measure themass of peptides and comparing the experimental masses with thetheoretical masses of peptides derived from the digestion in silico ofthe free antigen allows identification of the peptides; MS/MS analysiscan be performed to confirm the sequence of a peptide if necessary.

The spectrum of the eluate after chymotrypsin digestion reveals thepresence of peptides with a mass of: 912.49; 1086.47; 1843.03; 2104.16;1944.97; 1564.73; 1835.97; 2022.05; 2424,22et 2858.42 Da, which maycorrespond to antigen peptides in Table 10 below.

TABLE 10 Peptides obtained after chymotrypsin digestion(sequences protected from proteolysis) Mass (Da) Sequence SEQ ID No: 912.49 FIETKKF 115 1843.03 RKLQEIYFIETKKF 118 2104.16 NFRKLQEIYFIETKKF119 1944.97 DLSVIYREGANDFVVTF 120 1564.73 VVTFNTSHLQKKY 121 1835.97EIKVRSIPDHYFKGF 122 2022.05 EIKVRSIPDHYFKGFW 123 2424.22EIKVRSIPDHYFKGFWSEW 124 2858.42 EIKVRSIPDHYFKGFWSEWSPSY 125 1086.47FKGFWSEW 126

The spectrum of the eluate after Glu-C digestion reveals the presence ofdigestive peptides of our protein of interest with a mass of 1200.43;1309.68; 2108.97; 2191.04; 2699.43; 3170,68et 3264.70 Da may correspondto the antigen peptides in Table 11 below.

TABLE 11 Peptides obtained after Glu-C digestion(sequences protected from proteolysis) SEQ Mass (Da) Sequence ID No:2699.43 IYFIETKKFLLIGKSNICVKVGE 127 3264.70 KSLTCKKIDLTTIVKPEAPFDLSVIYRE128 2191.04 LTTIVKPEAPFDLSVIYRE 129 1309.68 APFDLSVIYRE 130 3170.68NKWTHVNLSSTKLTLLQRKLQPAAMYE 131 2108.97 IKVRSIPDHYFKGFWSE 132

The two digestions allowed us to identify three sites (Table 12 below)involved in the interaction between hN131B2 and CD127 antigen. Peptidesderived from the salt buffer washes were excluded to restrict thesequences of interest.

TABLE 12 Sequences of the human CD127 peptides protectedby N13B2 against proteolysis A (SEQ ID No: 115) FIETKKFB (SEQ ID No: 116) DLSVIY C (SEQ ID NO: 117) FKGF

The epitope mapping of the N13B2 antibody on the antigen CD127 showed 3different sequences important for the antibody activity on IL7/CD127pathway (FIG. 27 ). With the 3D crystallography analysis of theIL7/CD127 interaction (McElroy et al, Structure 2009, PDB:3DI2), two ofthe sequences (Seq ID N^(o) 115 and ID N^(o) 117) are structurallyclosed and are located in the region involved in the binding of the IL7with CD127. The third identified sequence (seq ID N^(o) 116) is locatedin the site 2b of the D2 domain of the receptor, domain predicted tointeract with CD132, the gamma chain of the receptor (Walsh et al,2012). N13B2 recognizes a conformational epitope on CD127 located in 2parts of the protein that inhibits the IL7-CD127 interaction and theCD127-CD132 heterodimer formation. The binding of the N13B2 mustdestabilize the formation of the “ternary IL7Ra/IL7/g-chain complex” aspredicted by Walsh ST, which block the internalization of the complex.

Example 19. Results

As previously described (Henriques et al., 2010), IL-7 alone inducesrapid internalization (30-40%) of IL-7 receptor alpha chain (CD127) atthe surface of T lymphocytes, which is required for IL-7 mediatedsignaling. Here we described that N13B2 mAb prevents the IL-7-inducedinternalization of CD127 and does not induce this internalization byitself (FIG. 16 ). In contrast, we described that anti-human CD127 1A11clone from GSK (patent application WO2011094259) dramatically decreasesthe expression of CD127 at the surface of T lymphocytes when appliedalone or in combination with IL-7 at 37° C. (FIG. 16 ). This effect wasobserved using different staining with several commercial anti-IL7Rantibodies (eBioRDR5 and MB15-18C9, data not shown). After intravenousadministration of chimeric N13B2 mAb (formatted with a human IgG1 orIgG4 Fc-domain) at 10 mg/Kg in non-human primates, we did not measurereduction of CD127 expression at the surface of T-lymphocytes over a2-week period of follow-up (FIG. 17B). In contrast, in other non-humanprimates treated in parallel intravenously with 10 mg/kg of theanti-human CD127 MD707-13 clone (formatted with human IgG4 Fc-domain;WO2013/056984), we observed a significant decrease (60%) of CD127 at thesurface of T-lymphocytes (FIG. 17B). This internalization of CD127 afterbinding of anti-human CD127 mAb on T-lymphocytes, was also previouslypublished by a Pfizer group, where they described that their anti-humanCD127 mAb (clone HAL-H3L4, U.S. Pat. No. 8,637,273) significantlyinduces CD127 internalization ex-vivo on human and non-human primateblood cells, as well as in-vivo after intravenous administration innon-human primates (Kern et al., 2013).

In a recent publication by Kern et al. (Kern et al., 2015), the CD127occupancy was studied and competition assays were performed. Theanti-CD127 HIL-7R-M21 clone from BD biosciences was shown to competewith HAL/Ab1 antibody (from Pfizer group) for the binding to CD127. Asshown in FIG. 16 of the present invention, the HAL antibody (clone H3L4,U.S. Pat. No. 8,637,273) was compared to N13B2 and 1A11 in terms ofCD127 expression and internalization. These results showed a competitionbetween the HAL antibody and the HIL-7R-M21 patent, confirming the dataof Kern et al, 2015. However, N13B2 does not compete with HIL-7R-M21.Kern et al. also showed that HAL/Ab1 by itself induces an in vivo downregulation of CD127 expression at the cell surface from 4 to 8 daysafter injection. Those results are comparable with the results presentedFIG. 17B of the present invention with the MD707-13 clone. FIG. 17Bshows a down regulation of CD127 expression at the cell surface 4 to 10days after injection of the antibody. This in vivo effect can becorrelated with the in vitro MD707-13-dependent internalization of CD127into the cell observed as well.

The epitope study by peptide microarray and mass spectrometry identifieda conformational epitope recognized by N13B2 on CD127. This epitope islocated in domains D1 and D2, in contrast with the antibodies of theprior art which recognize an epitope located only in D1 (Example 17).Furthermore, FIG. 16 shows that prior art antibodies induceinternalization of CD127, while N13B2 does not. We therefore concludethat the property of the N13B2 not to induce the CD127 internalizationis correlated with its property to recognize an epitope located in bothdomains D1 and D2.

Altogether, these results and previous reported showed that anti-humanCD127 mAbs (1A11 clone, HAL/Ab1 and H3L4 clones and MD707-13 clone)described to block the binding of IL-7 on IL-7 receptor, also induceIL-7 receptor alpha chain internalization which was associated andrequired for IL-7 receptor signaling. In contrast and in a surprisingmanner, N13B2 mAb has the unique property not to induce CD127internalization and it prevents such internalization induced by IL-7.These results have to be correlated with the observation thatCD127-internalization inducer mAb (for example MD707-13 clone), whichare effective in vitro to prevent IL-7 receptor signaling (for exampleSTAT5 phosphorylation, FIG. 14B), are not able in vivo to prevent memorycellular (FIG. 21 ) or humoral (FIG. 22 ) immune responses. In contrast,we described that N13B2 mAb, which effectively blocks IL-7 receptorsignaling (STAT5 phosphorylation) but does not induce CD127internalization ex vivo on human T lymphocytes and in vivo in non-humanprimates, prevents delayed-type hypersensitivity memory cellularresponses (FIG. 21 ) as well as immunization against xenogeneic sheepred blood cells (FIG. 22 ). While no difference was observed betweenisotype of N13B2 on the control of memory humoral response, we noticedthat IgG4-formatted N13B2 was more effective to prevent memory cellularresponses as compared to IgG1. No difference in term of mAb exposure andserum concentrations was observed between MD707-13-treated andN13B2-treated animals. Similarly, we observed also a significantincrease of regulatory T lymphocytes in animals treated with eitherN13B2 or MD707-13 mAb (FIG. 22 ).

Human IL-7 induced strong expression of α4 and β7 integrins in vitro onhuman T lymphocytes and dramatically increased the frequency of human Tlymphocytes expressing α4, β7 and α4/β7 integrins (FIG. 19A), which arerequired for T lymphocytes homing and retention in non-lymphoid tissuessuch as intestine, brain and skin (Gorfu et al., 2009, DeNucci et al.,2009). Accordingly, we observed that N13B2 mAb dose-dependently inhibitsin vitro both expression of α4 and β7 as well as decreases the frequencyof α4-positive and α4/β7-positive human T lymphocytes (FIG. 19B).Similarly, after transferred from human peripheral blood mononuclearcells into immunodeficient mice, we observed that the N13B2 antibodysignificantly and rapidly decreases the percentage of the β7-positive Tlymphocytes as well as the number (i.d. engraftment) of these cellsafter one (data not shown) and two weeks of treatment (FIG. 20 ).Results obtained in two different models of inflammation show that theN13B2 anti-IL7Rα antibody could be an efficient treatment againstinflammatory diseases and in particular in colitis.

Example 20. Generating a Conformational Epitope

CLIPS peptides may be used to adequately mimic the native secondary andtertiary structure of the antigen in the aim to translate these CLIPSpeptides into active and potent immunogens that induce the desiredantibodies (Boshuizen et al, 2014). The CLIPS technology involves the(multiple) cyclization of linear peptides via reaction with a smallrigid entity (chemical scaffold) that carries 2, 3 or 4 anchor points.The anchors react exclusively with one type of functionalities of thepeptide (i.e. thiols) and attaches to the peptide via multiple covalentbonds. The peptide folds around the scaffold and looses flexibilitywhile slowly adopting a well-defined three-dimensional structure, withthe scaffold entity in the center like the “spider in the web”.

The technology makes use of fully synthetic, tailor-made scaffolds.CLIPS scaffolds vary mainly in size, polarity, rigidity, solubility,functionality, and ‘SS-spanning’ distance. These scaffolds are used toaffix the loose ends of the peptide. When positioned appropriatelywithin the peptide sequence, the resulting CLIPS peptide is likely toresemble much better the 3D-structure of the corresponding region on theintact protein as compared to the linear sequence. TheCLIPS-cyclizations can be performed on native L-cysteine residues, butalso on artificially introduced D- and L-(homo)cysteines at virtuallyany desired position in the sequence. Hence, the structure anddimensions of the CLIPSed peptides can be varied at will. Thecyclization reaction lasts no longer than 30 min, runs at roomtemperature and does not require any sort of catalysis. Moreover, it canbe applied under fully aqueous conditions and neutral pH (7.5-8.0) andis therefore compatible with highly sensitive biological systems, likebacterial phages. Finally, the reaction can be run at high-dilutionconditions (10-100 μM), which promotes high yields of cyclic productsand avoids polymerization. This technology is highly versatile, andunique for its ease of application.

In an attempt to reconstruct both linear and discontinuous epitopes foranti-receptor antibody, linear multi-mer overlapping peptides aresynthesized directly onto credit-card-sized polypropylene plates withthe C terminus covalently coupled to the bottom of each 3 ul well (455wells per plate), and each well containing a different peptide. Withineach of the single-domain peptides, a cyclized dicysteine bridge wasformed to insert a constrained loop in the plate-attached peptides.Teeling et al, 2006, explain how to generate cyclized peptides withpeptides of interest in the aim to reconstitute discontinuous epitoperecognized by the antibody of interest. Briefly, plate-bound dicysteinecontaining peptides are first synthesized with cysteines spaced atbetween 4 and 13 aa along the peptide, for example, CXXXXC-plate,XXXCXXXXCXXXXXXplate, or CXXXXC-plate, etc. The peptides are thencyclized by treating with a,a-dibromoxylene in aqueous solution toprovide cysteine loops containing different numbers of amino acids. Thischemical modification provides more stable loops, than do disulfidebridges. (Niederfellner et al, 2011)

Example 21. Co-Immunoprecipitation of CD127 and γc

To test the effect of the N13B2 and of prior art antibodies on thebinding of CD127 to the γc chain, a coimmunoprecipitation experiment wasperformed in cells stimulated by IL-7 and incubated in the absence ofantibodies or in the presence of MD707-13 or of N13B2 antibodies. In theabsence of antibodies, CD127 and γc were shown to coimmunoprecipitate.The incubation of cells with MD707-13 did not prevent thiscoimmunoprecipitation, while the incubation with N13B2 led to theabsence of such coimmunoprecipitation. Our antibody therefore is capableof disrupting the binding of CD127 to the γc chain, while antibodies ofthe prior art do not have such a feature.

To co-immunoprecipitate complex CD127-CD132-IL7 in presence ofanti-CD127, human PBL were incubated with rat anti-hCD127 antibody (ratN13B2 or MD707-13 at 10 μg/ml) for 30 min at 37° C., before stimulatingwith IL7 (AbD Serotec, ref PHP046) at 5 ng/ml for 15 min at 37° C.Reaction was stopped at 4° C., and washed twice with cold-PBS beforeadding lysis buffer from co-immuprecipitation kit (Pierce Direct IP kit,ref 26148).

A purification column anti-human CD127 was prepared with theco-immuprecipitation kit (Pierce Direct IP kit, ref 26148). The columnwas coupled with 75 μg of a non-competing rat anti-human CD127(Effimune, MD707-9), following the procedure recommended by themanufacturer. The lysate was pre-purified on a non-coupled column inorder to remove unspecific binder. Then, lysate was added on theanti-CD127 column and incubated 2 h at 4° C., on rolling agitation. Thecolumn was washed twice with washing buffer, and then was eluted withelution buffer. Recovered sample were analysed by Western Blot.

For Western Blot, SDS-Page gel was prepared (10% for resolving, 4% forstacking gel, with 1.5 mm thickness) and 50 μl of denaturated eluate(for denaturation: DTT 0.1M and 10 min at 95° C.) was adding in eachwell. CD127Fc (Sino Biologicals, Beijing, China; reference 10975-H08H)and CD132Fc (Sino Biologicals, Beijing, China; reference 10555-H02H)recombinant protein was added (5 μg/well) as a control for western blotdetection. After migration for 1 h30 at 200V, and transfer onnitrocellulose membrane for 35 min at 20V, saturation was performed for2 h at room-temperature in 5% milk.

To start detection, rabbit anti-human CD132 antibody(anticorps-en-ligne, France, reference ABIN741840) is added at 1/50overnight at 4° C., then revealed with peroxidase-labeled goatanti-rabbit (Jackson Immunoresearch, reference 111-035-144) at 1/2000for 1 h at room-temperature. After dehybridization, the membrane wasincubated with rat anti-human CD127 antibody (Effimune, MD707-9) at1/200 overnight at 4° C., and revealed with peroxidase-labeled donkeyanti-rat antibody (Jackson Immunoresearch, reference 712-035-153) at1/1000 for 1 h at room-temperature. For each revelation, ECL (ThermoScientific, reference 34080) was used to detect peroxidase bychemiluminescence, and the results was read on Fuji 4000 camera.

FIG. 28 shows the results of the co-immunoprecipitation of theCD127/IL7/CD132 complex. We observed that the CD132 chain (60 KDa)co-immunoprecipitates with CD127 in any conditions except when cells areincubated with the N13B2 antibody (28A). However, in each conditionCD127 (70 KDa) is well immunoprecipitated by de MD707-9 antibody asshown by FIG. 28B indicating that N13B2 and MD707-13 did not competewith MD707-9 for the recognition of the CD127. The N13B2 antibodyinhibits the complex formation of CD127/CD132 in the presence of IL-7.These results are consistent with the epitope mapping of the N13B2antibody on CD127, showing that N13B2 binds an amino acid sequencewithin site 2b in domain D2 of the IL7R alpha chain (Walsh et al,Immunol rev. 2012).

Altogether these results showed that N13B2 antibody is an antagonist ofthe IL7/CD127 interaction as well as an antagonist of the CD127/CD132interaction at site 2b in the presence of IL-7, which could explain theinhibitory activity of the antibody against the internalization of CD127observed with IL7 and/or anti-CD127 antibodies from the prior art.

The Following Numbered Embodiments Constitute Preferred Embodiments ofthe Invention.

-   -   1. An antibody or an antigen-binding fragment of an antibody or        an antigen-binding antibody mimetic which binds specifically to        CD127 and does not induce the internalization of CD127.    -   2. An antibody or antigen-binding fragment or mimetic thereof,        in particular according to embodiment 1, which inhibits        IL7-induced internalization of CD127.    -   3. An antibody or antigen-binding fragment or mimetic thereof        according to embodiment 1 or 2 wherein the cell surface        expression of CD127 in IL-7 treated cells in the presence of        antibody or fragment is at least 80%, preferably at least 90% of        its level in cells incubated in the absence of antibody.    -   4. An antibody or antigen-binding fragment thereof which binds        specifically to CD127 and thereby disrupts the binding of CD127        to the γc common chain of cytokine receptors.    -   5. An antibody or antigen-binding fragment thereof according to        any of embodiments 1 to 3, which disrupts the binding of CD127        to the γc common chain of cytokine receptors when bound to        CD127.    -   6. An antibody or antigen-binding fragment thereof according to        any of embodiments 4 or 5, in the presence of which the amount        of γc bound to CD127 is less than 80%, preferably less than 50%,        even more preferably less than 25% or 10% of said amount        measured in the absence of antibodies in otherwise identical        conditions, in particular when said measurement is performed on        cell lysates comprising CD127-containing molecular complexes        from intact cells expressing the IL7 receptor at the cell        surface, incubated in the presence or absence of said        antibodies.    -   7. An antibody or antigen-binding fragment or mimetic thereof        according to any of the above embodiments, which is an        antagonist of IL-7R signaling induced by IL-7.    -   8. An antibody or antigen-binding fragment or mimetic thereof,        in particular according to any of the above embodiments, which        specifically binds and/or has been raised against an antigen        according to any of embodiments 53 to 67 or the epitope of said        antigen.    -   9. An antibody or antigen-binding fragment or mimetic thereof,        which binds specifically to CD127, in particular according to        any of the above embodiments, which does not increase the        maturation of dendritic cells induced by TSLP.    -   10. An antibody or antigen-binding fragment or mimetic thereof        according to any of the above embodiments which inhibits the        expression of α4, β7 and/or α4/β7 integrins.    -   11. An antibody or antigen-binding fragment or mimetic thereof        according to embodiment 10 which inhibits the expression of α4,        β7 and/or α4/β7 integrins in vivo, in particular in human T        cells injected in an immunodeficient mouse.    -   12. An antibody or antigen-binding fragment or mimetic thereof,        which binds specifically to CD127, in particular according to        any of the above embodiments, comprising a VH chain comprising        at least one of the following amino acid sequences:        -   VHCDR1 SEQ ID No:10;        -   VHCDR2 SEQ ID No:12;        -   VHCDR3 SEQ ID No:14 or SEQ ID No:48; or        -   VH SEQ ID No:22            and/or a VL chain comprising at least one of the following            amino acid sequences:    -   VLCDR1 SEQ ID No:16 or SEQ ID No:50;    -   VLCDR2 SEQ ID No:18 or SEQ ID No:52;    -   VLCDR3 SEQ ID No:20; or    -   VL SEQ ID No:24.    -   13. An antibody or a fragment or mimetic thereof according to        embodiment 12 which comprises at least two, three, four or five        CDR sequences selected from the group consisting in VHCDR1 SEQ        ID No:10, VHCDR2 SEQ ID No:12, VHCDR3 SEQ ID No:14 or SEQ ID        No:48, VLCDR1 SEQ ID No:16 or SEQ ID No:50, VLCDR2 SEQ ID No:18        or SEQ ID No:52 and VLCDR3 SEQ ID No:20.    -   14. An antibody or a fragment or mimetic thereof according to        embodiment 13 which comprises all six CDR sequences VHCDR1 SEQ        ID No:10, VHCDR2 SEQ ID No:12, VHCDR3 SEQ ID No:14 or SEQ ID        No:48, VLCDR1 SEQ ID No:16 or SEQ ID No:50, VLCDR2 SEQ ID No:18        or SEQ ID No:52 and VLCDR3 SEQ ID No:20.    -   15. An antibody according to embodiment 14 wherein        -   the VH chain consists in the VH chain with the sequence of            SEQ ID No:2 or of SEQ ID No:6 or of SEQ ID No:54 or            comprises the sequence of SEQ ID No:22 or of SEQ ID No:36 or            of SEQ ID No:38 or of SEQ ID No:40; and        -   the VL chain consists in the VL chain with the sequence of            SEQ ID No:4 or of SEQ ID No:56 or comprises the sequence of            SEQ ID No:24 or of SEQ ID No:42 or of SEQ ID No:44 or of SEQ            ID No:46.    -   16. An antibody according to any of the above embodiments which        is a chimeric antibody or a humanized antibody or a deimmunized        antibody.    -   17. An antibody according to embodiment 13 which is a humanized        and deimmunized antibody, wherein the heavy chain has the        sequence of SEQ ID No:52 and the light chain has the sequence of        SEQ ID No:54.    -   18. A macromolecule which is a chimeric molecule comprising an        antibody or an antigen-binding fragment or mimetic thereof        according to any of the above embodiments, wherein said antibody        is associated with a functionally different molecule, said        chimeric molecule being either a fusion chimeric protein or a        conjugate resulting from covalent attachment of a chemical group        or molecule, such as a PEG polymer or a labelled antibody.    -   19. A macromolecule according to any of the above embodiments,        which is an affitin or an anticalin.    -   20. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof, according to any of        the above embodiments which binds CD127 with a Kd lower than        5E-10 M, especially lower than 1E-10 M, especially lower than        5E-11 M.    -   21. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof, according to any of        the above embodiments which exhibits cytotoxic activity towards        CD127-positive cells.    -   22. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof, according to any of        the above embodiments which does not increase the maturation of        dendritic cells induced by TSLP, wherein the increase in        dendritic cell maturation induced by TSLP is assessed by        determining an elevated expression of cell surface marker CD40        and/or CD80 in TSLP receptor-positive cells treated with TSLP        and with said macromolecule compared to cells treated with TSLP        alone.    -   23. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof, according to        embodiment 22 wherein the expression of CD80 is elevated by no        more than 25%, preferably no more than 10%, in TSLP        receptor-positive cells treated with TSLP and with said        macromolecule, compared to cells treated with TSLP alone.    -   24. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof, according to        embodiment 23 wherein the expression of CD80 is not elevated or        is decreased in TSLP receptor-positive cells treated with TSLP        and with said macromolecule, compared to cells treated with TSLP        alone.    -   25. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof according to        embodiment 22 wherein the expression of CD40 is elevated by no        more than 50%, preferably no more than 25%, in TSLP        receptor-positive cells treated with TSLP and with said        macromolecule compared to cells treated with TSLP alone.    -   26. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof, according to        embodiment 25 wherein the expression of CD40 is not elevated or        is decreased in TSLP receptor-positive cells treated with TSLP        and with said macromolecule, compared to cells treated with TSLP        alone.    -   27. A nucleic acid molecule encoding an antibody or        antigen-binding fragment thereof, or macromolecule of any of the        above embodiments.    -   28. A nucleic acid molecule according to embodiment 27 which        encodes an amino acid chosen from the group consisting of SEQ ID        No:2; SEQ ID No:4; SEQ ID No:6; SEQ ID No:8; SEQ ID No:10; SEQ        ID No:12; SEQ ID No:14; SEQ ID No:16; SEQ ID No:18; SEQ ID        No:20; SEQ ID No:22; SEQ ID No:24; SEQ ID No:36; SEQ ID No:38;        SEQ ID No:40; SEQ ID No:42; SEQ ID No:44; SEQ ID No:46; SEQ ID        No:48; SEQ ID No:50; SEQ ID No:52; SEQ ID No:54 and SEQ ID        No:56.    -   29. A nucleic acid molecule according to embodiment 28 which is        chosen from the group consisting of SEQ ID No:1; SEQ ID No:3;        SEQ ID No:5; SEQ ID No:7; SEQ ID No:9; SEQ ID No:11; SEQ ID        No:13; SEQ ID No:15; SEQ ID No:17; SEQ ID No:19; SEQ ID No:21;        SEQ ID No:23; SEQ ID No:35; SEQ ID No:37; SEQ ID No:39; SEQ ID        No:41; SEQ ID No:43; SEQ ID No:45; SEQ ID No:47; SEQ ID No:49;        SEQ ID No:51; SEQ ID No:53 and SEQ ID No:55.    -   30. A vector for the cloning and/or for the expression of a        polynucleotide of any of embodiments 27 to 29, especially a        plasmid, suitable for cloning and/or expressing in mammalian        cells.    -   31. A cell or a cell line recombined with a polynucleotide        according to any of embodiments 27 to 30, especially a mammalian        cell or cell line.    -   32. A pharmaceutical composition comprising a macromolecule, in        particular an antibody or antigen-binding fragment or mimetic        thereof, according to any of embodiments 1 to 26, with a        pharmaceutical vehicle, wherein said pharmaceutical composition        optionally comprises a further, different, active ingredient.    -   33. A pharmaceutical composition comprising as a therapeutically        active ingredient a macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof, according to any of        embodiments 1 to 26 or a pharmaceutical composition of        embodiment 32 in a formulation suitable for controlling        dendritic cell differentiation/maturation when administered to a        human patient.    -   34. A pharmaceutical composition of embodiments 32 or 33, which        further comprises an additional compound having a therapeutic        immunomodulator effect in particular on cells involved in an        autoimmune disease or an allergic disease, leukemia such as        acute lymphoblastic leukemia, lymphoma, a cancer disease, a        chronic viral infection, inflammatory diseases, transplantation,        respiratory diseases or autoimmunity.    -   35. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof according to any of        embodiments 1 to 26 or a nucleic acid of any of embodiments 27        to 30 or a cell or cell line of embodiment 31 for use as a        therapeutically active ingredient in a combination or in an        add-on therapeutic regimen in a patient in need thereof.    -   36. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof according to any of        embodiments 1 to 26 or a nucleic acid of any of embodiments 27        to 30 or a cell or cell line of embodiment 31 or a        pharmaceutical composition of any of embodiments 32 to 34 for        use in the treatment of a patient, in particular a human        patient, with a disease.    -   37. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof according to any of        embodiments 1 to 26 or a nucleic acid of any of embodiments 27        to 30 or a cell or cell line of embodiment 31 or a        pharmaceutical composition of any of embodiments 32 to 34 for        use in the treatment of a patient, in particular a human        patient, at risk of a disease.    -   38. A macromolecule, nucleic acid, cell, cell lines or        pharmaceutical composition for use according to embodiment 36        and/or embodiment 37, wherein the disease is an autoimmune        disease, in particular rheumatoid arthritis, multiple sclerosis,        type I diabetes, autoimmune thyroiditis and lupus.    -   39. A macromolecule, nucleic acid, cell, cell lines or        pharmaceutical composition for use according to embodiment 36        and/or embodiment 37, wherein the disease is an inflammatory        disease, in particular IBD and encephalomyelitis.    -   40. A macromolecule, nucleic acid, cell, cell lines or        pharmaceutical composition for use according to embodiment 36        and/or embodiment 37, wherein the disease is an allergic        disease.    -   41. A macromolecule, nucleic acid, cell, cell lines or        pharmaceutical composition for use according to embodiment 36        and/or embodiment 37, wherein the disease is a cancer disease.    -   42. A macromolecule, nucleic acid, cell, cell lines or        pharmaceutical composition for use according to embodiment 36        and/or embodiment 37, wherein the disease is a respiratory        diseases.    -   43. A macromolecule, nucleic acid, cell, cell lines or        pharmaceutical composition for use according to embodiment 36        and/or embodiment 37, wherein the disease is related to, in        particular is a consequence of, transplantation.    -   44. A method of treatment comprising the administration of a        macromolecule, in particular an antibody or antigen-binding        fragment or mimetic thereof according to any of embodiments 1 to        26 or a nucleic acid of any of embodiments 27 to 30 or cell or        cell line of embodiment 31 or pharmaceutical composition of        embodiments 32 to 34 in a patient with or at risk of a disease.    -   45. A method of treatment according to embodiment 44, wherein        the disease is an autoimmune disease, in particular rheumatoid        arthritis, multiple sclerosis, type I diabetes, autoimmune        thyroiditis and lupus.    -   46. A method of treatment according to embodiment 44, wherein        the disease is an inflammatory disease, in particular IBD and        encephalomyelitis.    -   47. A method of treatment according to embodiment 44, wherein        the disease is an allergic disease.    -   48. A method of treatment according to embodiment 44, wherein        the disease is a cancer disease.    -   49. A method of treatment according to embodiment 44, wherein        the disease is a respiratory diseases.    -   50. A method of treatment according to embodiment 44, wherein        the disease is related to, in particular is a consequence of,        transplantation.    -   51. A macromolecule, in particular an antibody or        antigen-binding fragment or mimetic thereof according to any of        embodiments 1 to 26 or a nucleic acid of any of embodiments 27        to 30 or a cell or cell line of embodiment 31 or a        pharmaceutical composition of any of embodiments 32 to 34 for        use in the treatment of a patient, in particular a human        patient, in need of transplantation and/or about to be        transplanted and/or in a transplanted patient.    -   52. A method of treatment comprising the administration of a        macromolecule, in particular an antibody or antigen-binding        fragment or mimetic thereof according to any of embodiments 1 to        26 or a nucleic acid of any of embodiments 27 to 30 or cell or        cell line of embodiment 31 or pharmaceutical composition of        embodiments 32 to 34 in a patient in need of transplantation        and/or about to be transplanted and/or in a transplanted        patient.    -   53. An antigen wherein the epitope comprises or consists of        sequences from site 2b of CD127, in particular comprising at        least 3, 4, 5, 6 or 7 consecutive amino acids from site 2b of        CD127.    -   54. An antigen according to embodiment 53, wherein the epitope        comprises or consists of sequences from the site consisting of        amino acids 109 to 127 of SEQ ID No:114, in particular from the        site consisting of amino acids 110 to 125, 112 to 125, 112 to        120, in particular comprising at least 3, 4, 5, 6 or 7        consecutive amino acids from said site.    -   55. An antigen according to any of embodiments 53 or 54, wherein        the epitope comprises at least 3, 4, 5, 6 or 7 consecutive amino        acids of CD127, said consecutive amino acids comprising P112        and/or L115.    -   56. An antigen according to any of embodiments 53 to 55, wherein        the epitope consists of or comprises the sequence of SEQ ID        No:116, in particular comprises the sequence of SEQ ID No:86.    -   57. An antigen according to any of embodiments 53 to 56, wherein        the epitope also comprises sequences, in particular at least 3,        4, 5, 6 or 7 consecutive amino acids, from the D1 domain of        CD127, in particular from amino acids 1-98 of SEQ ID No:114.    -   58. An antigen according to embodiment 57, wherein the epitope        comprises the sequence of human CD127 comprising or consisting        of the sequence of SEQ ID No:115, in particular comprising or        consisting of SEQ ID No:110    -   59. An antigen according to any of embodiments 53 to 58, wherein        the epitope also comprises sequences, in particular at least 3,        4, 5, 6 or 7 consecutive amino acids, from amino acids 180-220        of SEQ ID No:114, in particular wherein said sequences from        amino acids 180-220 of SEQ ID No:114 consists of or comprises        the sequence of SEQ ID No:117, in particular comprises or        consists of SEQ ID No:111.    -   60. An antigen according to any of embodiments 53 to 59, wherein        the epitope consists of or comprises the sequences of human        CD127 consisting of:        -   the sequence of SEQ ID No:110 or the sequence of SEQ ID            No:115;        -   the sequence of of SEQ ID No:111 or the sequence of SEQ ID            No:117; and        -   the sequence of SEQ ID No:86 or the sequence of SEQ ID            No:116.    -   61. An antigen according to any of embodiments 53 to 60, wherein        the epitope does not comprise more than 3, 4 or 5 consecutive        amino acids from the sequence of amino acids 99-108 of SEQ ID        No:114 and/or does not comprise more than 3, 4 or 5 consecutive        amino acids from the sequence of amino acids 128-179 of SEQ ID        No:114, and/or does not comprise more than 3, 4 or 5 consecutive        amino acids from the sequence of amino acids 220-239 of SEQ ID        No:114, in particular does not comprise more than 3, 4 or 5        consecutive amino acids from any of said amino acid sequences of        SEQ ID No:114.    -   62. An antigen according to any of embodiments 53 or 60, wherein        the epitope sequence of human CD127 comprising SEQ ID No:110        does not extend to comprise the amino acids adjacent to said        sequence in the sequence of human CD127 by more than 1        N-terminal amino acid or by more than 7 C-terminal amino acids.    -   63. An antigen according to embodiment 61, wherein the epitope        sequence of human CD127 comprising SEQ ID No:110 does not extend        to comprise any of the N-terminal and/or C-terminal amino acids        adjacent to said sequence in the sequence of human CD127.    -   64. An antigen according to any of embodiments 53 to 63, wherein        the epitope sequence of human CD127 comprising SEQ ID No:111        does not extend to comprise the amino acids adjacent to said        sequence in the sequence of human CD127 by more than 30        N-terminal amino acid or by more than 30 C-terminal amino acids.    -   65. An antigen according to embodiment 64, wherein the epitope        sequence of human CD127 comprising SEQ ID No:111 does not extend        to comprise any of the N-terminal and/or C-terminal amino acids        adjacent to said sequence in the sequence of human CD127.    -   66. An antigen according to any of embodiments 53 to 65, wherein        the epitope is a conformational epitope, in particular wherein        the peptides from CD127 comprised in said epitope are in a        conformation which mimics the conformation of the corresponding        peptides in the native CD127 or the extracellular domain        thereof, in particular in CD127 in its monomeric form without        ligand, in its form bound to γc and/or in its form bound to IL7.    -   67. An antigen according to embodiment 66, wherein the epitope        is a conformational epitope, in which the peptides from CD127        are bound to a rigid molecular backbone which maintains them in        the desired conformation, in particular such an antigen obtained        using the CLIPS technology.    -   68. An epitope as defined in any of embodiments 53 to 67.    -   69. A nucleic acid encoding an antigen as defined by any of        embodiments 53 to 67.    -   70. A method of manufacturing an antibody comprising immunizing        a non-human animal against an antigen as defined in any of        embodiments 53 to 67.    -   71. A method of selecting an antibody, a fragment of an antibody        or an antibody mimetic, in particular an antibody obtained as in        embodiment 70 of fragment of mimetic thereof, comprising a step        of assaying the binding capacity of said antibody to at least        one antigen as defined in any of embodiments 53 to 67, in        particular wherein said method comprises several successive such        steps, each step assaying the binding capacity to a distinct        peptide consisting of a single contiguous sequence of CD127.    -   72. A method of selecting a macromolecule, in particular an        antibody, in particular an antibody obtained as in embodiment        70, or an antigen-binding fragment or mimetic of such an        antibody, comprising or consisting of a step of testing the        binding capacity of the macromolecule to CD127, in particular to        an antigen thereof as defined in any of embodiments 53 to 67 and        optionally selecting macromolecules according to embodiment 20.    -   73. A method of selecting a macromolecule according to any of        embodiments 71 or 72, wherein the antigen comprises several        non-contiguous peptides of CD127 and wherein the method        comprises several steps, each of said step consisting of testing        the binding capacity of the macromolecule to one of said        peptides of CD127.    -   74. A method, in particular according to any of embodiments 71        to 73, of selecting a macromolecule, in particular an antibody,        in particular an antibody obtained as in embodiment 70, or an        antigen-binding fragment or mimetic of such an antibody,        comprising or consisting of the step of testing the        internalization of CD127 in CD127-expressing cells induced by        the presence of the macromolecule.    -   75. A method, in particular according to any of embodiments 71        to 74, of selecting a macromolecule, in particular an antibody,        in particular an antibody obtained as in embodiment 70, or an        antigen-binding fragment or mimetic of such an antibody,        comprising or consisting of the step of testing the inhibition        by the macromolecule of IL7-induced internalization of CD127 in        CD127-expressing cells and optionally selecting macromolecules        according to embodiment 3.    -   76. A method, in particular according to any of embodiments 71        to 75, of selecting a macromolecule, in particular an antibody,        in particular an antibody obtained as in embodiment 70, or an        antigen-binding fragment or mimetic of such an antibody,        comprising or consisting of the step of assaying the capacity of        said macromolecule to disrupt, by its binding to CD127, the        binding of CD127 to the γc chain.    -   77. A method, in particular according to any of embodiments 71        to 76, of selecting a macromolecule, in particular an antibody,        in particular an antibody obtained as in embodiment 70, or an        antigen-binding fragment or mimetic of such an antibody,        comprising or consisting of the step of testing the increase of        the maturation of DCs induced by TSLP in the presence of the        macromolecule and optionally selecting macromolecules according        to any of embodiments 22 to 26.    -   78. A method according to any of embodiments 71 to 77, further        comprising one or more of the following steps:        -   a. Testing the inhibition by the macromolecule of IL-7            induced signalling, in particular STAT5 phosphorylation;        -   b. Testing the inhibition by the macromolecule of            TSLP-induced production of TARC;        -   c. Testing the inhibition by the macromolecule of the            expression of α4, β7 and/or α4/β7 integrin expression, in            particular cell surface expression on T-lymphocytes.

REFERENCES

-   Adams, A. B., Pearson, T. C., and Larsen, C. P. (2003). Heterologous    immunity: an overlooked barrier to tolerance. Immunol. Rev. 196,    147-160.-   Albuquerque, A. S., Cortesão, C. S., Foxall, R. B., Soares, R. S.,    Victorino, R. M. M., and Sousa, A. E. (2007). Rate of increase in    circulating IL-7 and loss of IL-7Ralpha expression differ in HIV-1    and HIV-2 infections: two lymphopenic diseases with similar    hyperimmune activation but distinct outcomes. J. Immunol. Baltim. Md    1950 178, 3252-3259.-   Baca, M., Presta, L. G., O'Connor, S. J., and Wells, J. A. (1997).    Antibody humanization using monovalent phage display. J. Biol. Chem.    272, 10678-10684.-   Van Bodegom, D., Zhong, J., Kopp, N., Dutta, C., Kim, M.-S., Bird,    L., Weigert, O., Tyner, J., Pandey, A., Yoda, A., et al. (2012).    Differences in signaling through the B-cell leukemia oncoprotein    CRLF2 in response to TSLP and through mutant JAK2. Blood 120,    2853-2863.-   Boshuizen, R. S., Marsden, C., Turkstra, J., Rossant, C. J.,    Slootstra, J., Copley, C., and Schwamborn, K. (2014). A combination    of in vitro techniques for efficient discovery of functional    monoclonal antibodies against human CXC chemokine receptor-2    (CXCR2). mAbs 6, 1415-1424.-   Bour-Jordan, H., Esensten, J. H., Martinez-Llordella, M., Penaranda,    C., Stumpf, M., and Bluestone, J. A. (2011). Intrinsic and extrinsic    control of peripheral T-cell tolerance by costimulatory molecules of    the CD28/B7 family. Immunol. Rev. 241, 180-205.-   Broux, B., Hellings, N., Venken, K., Rummens, J.-L., Hensen, K., Van    Wijmeersch, B., and Stinissen, P. (2010). Haplotype 4 of the    multiple sclerosis-associated interleukin-7 receptor alpha gene    influences the frequency of recent thymic emigrants. Genes Immun.    11, 326-333.-   Chassoux, D. M., Linares-Cruz, L. G., Bazin, H., and    Stanislawski, M. (1988). K-cell-mediated cytotoxicity induced with    rat monoclonal antibodies. I. Antibodies of various isotypes differ    in their ability to induce cytotoxicity mediated by rat and human    effectors. Immunology 65, 623-628.-   Chothia, C., and Lesk, A. M. (1987). Canonical structures for the    hypervariable regions of immunoglobulins. J. Mol. Biol. 196,    901-917.-   Deininger, P. (1990). Molecular cloning: A laboratory manual: 2nd    ed. Edited by J. Sambrook, E. F. Fritsch, and T. Maniatis. Cold    Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 1989 (in 3    volumes). Anal. Biochem. 186, 182-183.-   Delves, P. J., Martin, S. J., Burton, D. R., and Roitt, I. M.    (2011). Roitt's Essential Immunology (John Wiley & Sons).-   Denucci, C. C., Mitchell, J. S., and Shimizu, Y. (2009). Integrin    function in T-cell homing to lymphoid and nonlymphoid sites: getting    there and staying there. Crit. Rev. Immunol. 29, 87-109.-   Dustin, M. L., and Shaw, A. S. (1999). Costimulation: building an    immunological synapse. Science 283, 649-650.-   Edward G. Routledge, S. D. G. (1993). Reshaping antibodies for    therapy. 13-44.-   Flavell, D. J., Warnes, S. L., Bryson, C. J., Field, S. A., Noss, A.    L., Packham, G., and Flavell, S. U. (2006). The anti-CD20 antibody    rituximab augments the immunospecific therapeutic effectiveness of    an anti-CD19 immunotoxin directed against human B-cell lymphoma.    Br. J. Haematol. 134, 157-170.-   Gaseitsiwe, S., Valentini, D., Mahdavifar, S., Reilly, M., Ehrnst,    A., and Maeurer, M. (2010). Peptide microarray-based identification    of Mycobacterium tuberculosis epitope binding to HLA-DRB1*0101,    DRB1*1501, and DRB1*0401. Clin. Vaccine Immunol. CVI 17, 168-175.-   Gorfu, G., Rivera-Nieves, J., and Ley, K. (2009). Role of beta7    integrins in intestinal lymphocyte homing and retention. Curr. Mol.    Med. 9, 836-850.-   Grakoui, A., Bromley, S. K., Sumen, C., Davis, M. M., Shaw, A. S.,    Allen, P. M., and Dustin, M. L. (1999). The immunological synapse: a    molecular machine controlling T cell activation. Science 285,    221-227.-   Haas, J., Korporal, M., Schwarz, A., Balint, B., and Wildemann, B.    (2011). The interleukin-7 receptor α chain contributes to altered    homeostasis of regulatory T cells in multiple sclerosis. Eur. J.    Immunol. 41, 845-853.-   Haudebourg, T., Poirier, N., and Vanhove, B. (2009). Depleting    T-cell subpopulations in organ transplantation. Transpl. Int.    Off. J. Eur. Soc. Organ Transplant. 22, 509-518.-   He, R., and Geha, R. S. (2010). Thymic stromal lymphopoietin.    Ann. N. Y. Acad. Sci. 1183, 13-24.-   Henriques, C. M., Rino, J., Nibbs, R. J., Graham, G. J., and    Barata, J. T. (2010). IL-7 induces rapid clathrin-mediated    internalization and JAK3-dependent degradation of IL-7Ralpha in T    cells. Blood 115, 3269-3277.-   Von Horsten, H. H., Ogorek, C., Blanchard, V., Demmler, C., Giese,    C., Winkler, K., Kaup, M., Berger, M., Jordan, I., and Sandig, V.    (2010). Production of non-fucosylated antibodies by co-expression of    heterologous GDP-6-deoxy-D-lyxo-4-hexulose reductase. Glycobiology    20, 1607-1618.-   Inaba, K., Inaba, M., Witmer-Pack, M., Hatchcock, K., Hodes, R., and    Steinman, R. M. (1995). Expression of B7 costimulator molecules on    mouse dendritic cells. Adv. Exp. Med. Biol. 378, 65-70.-   Jariwala, S. P., Abrams, E., Benson, A., Fodeman, J., and Zheng, T.    (2011). The role of thymic stromal lymphopoietin in the    immunopathogenesis of atopic dermatitis. Clin. Exp. Allergy J. Br.    Soc. Allergy Clin. Immunol. 41, 1515-1520.-   Kabat, E. A., Wu, T. T., Reid-Miller, M., Perry, H. M. and    Gottesman, K. S. (1992) Sequences of Proteins of Immunological    Interest (DIANE publishing, 1992).-   Kern, B., Kraynov, E., Lee, L.-F., Ray, R. (2013). Receptor    occupancy and internalization of an anti-IL-7 receptor antibody.    Cytokine 63, 276-277.-   Kern, B., Li, W., Bono, C., Lee, L.-F., and Kraynov, E. (2015).    Receptor occupancy and blocking of STAT5 signaling by an anti-IL-7    receptor α antibody in cynomolgus monkeys. Cytometry B Clin. Cytom.-   Krehenbrink, M., Chami, M., Guilvout, I., Alzari, P. M., Pécorari    F., Pugsley A. P. (2008). Artificial binding proteins (Affitins) as    probes for conformational changes in secretin PuID. J Mol Biol. 2008    Nov. 28.-   Lefranc, M.-P., Giudicelli, V., Ginestoux, C., Bodmer, J., Müller,    W., Bontrop, R., Lemaitre, M., Malik, A., Barbié, V., and Chaume, D.    (1999). IMGT, the international ImMunoGeneTics database. Nucleic    Acids Res. 27, 209-212.-   Lei, L., Zhang, Y., Yao, W., Kaplan, M. H., and Zhou, B. (2011).    Thymic Stromal Lymphopoietin Interferes with Airway Tolerance by    Suppressing the Generation of Antigen-Specific Regulatory T    Cells. J. Immunol. 186, 2254-2261.-   Luo, H., Wu, Z., Qi, S., Jin, W., Han, B., Wu, J. (2011). Ephrinb1    and Ephrinb2 are associated with interleukin-7 receptor α and retard    its internalization from the cell surface. J Biol Chem. 2011 Dec.    30; 286(52):44976-87.-   Martin, A. C. R. (2001). Protein Sequence and Structure Analysis of    Antibody Variable Domains. In Antibody Engineering, D. R.    Kontermann, and D. S. Dübel, eds. (Springer Berlin Heidelberg), pp.    422-439.-   Mazzucchelli, R., Hixon, J. A., Spolski, R., Chen, X., Li, W. Q.,    Hall, V. L., Willette-Brown, J., Hurwitz, A. A., Leonard, W. J., and    Durum, S. K. (2008). Development of regulatory T cells requires    IL-7Ralpha stimulation by IL-7 or TSLP. Blood 112, 3283-3292.-   McElroy, C. A., Dohm, J. A., and Walsh, S. T. R. (2009). Structural    and biophysical studies of the human IL-7/IL-7Ralpha complex.    Struct. Lond. Engl. 1993 17, 54-65.-   McElroy, C. A., Holland, P. J., Zhao, P., Lim, J.-M., Wells, L.,    Eisenstein, E., and Walsh, S. T. R. (2012). Structural    reorganization of the interleukin-7 signaling complex. Proc. Natl.    Acad. Sci. U.S.A. 109, 2503-2508-   Michel, L., Berthelot, L., Pettré, S., Wiertlewski, S., Lefrère, F.,    Braudeau, C., Brouard, S., Soulillou, J.-P., and Laplaud, D.-A.    (2008). Patients with relapsing-remitting multiple sclerosis have    normal Treg function when cells expressing IL-7 receptor alpha-chain    are excluded from the analysis. J. Clin. Invest. 118, 3411-3419.-   Nancey, S., Hamzaoui, N., Moussata, D., Graber, I., Bienvenu, J.,    and Flourie, B. (2008). Serum interleukin-6, soluble interleukin-6    receptor and Crohn's disease activity. Dig. Dis. Sci. 53, 242-247.-   Niederfellner, G., Lammens, A., Mundigl, O., Georges, G. J.,    Schaefer, W., Schwaiger, M., Franke, A., Wiechmann, K., Jenewein,    S., Slootstra, J. W., et al. (2011). Epitope characterization and    crystal structure of GA101 provide insights into the molecular basis    for type I/II distinction of CD20 antibodies. Blood 118, 358-367.-   Olivier, S., Jacoby, M., Brillon, C., Bouletreau, S., Mollet, T.,    Nerriere, O., Angel, A., Danet, S., Souttou, B., Guehenneux, F., et    al. (2010). EB66 cell line, a duck embryonic stem cell-derived    substrate for the industrial production of therapeutic monoclonal    antibodies with enhanced ADCC activity. mAbs 2, 405-415.-   Olkhanud, P. B., Rochman, Y., Bodogai, M., Malchinkhuu, E., Wejksza,    K., Xu, M., Gress, R. E., Hesdorffer, C., Leonard, W. J., and    Biragyn, A. (2011). Thymic stromal lymphopoietin is a key mediator    of breast cancer progression. J. Immunol. Baltim. Md 1950 186,    5656-5662.-   Van Oosterhout, Y. V., van Emst, J. L., Bakker, H. H., Preijers, F.    W., Schattenberg, A. V., Ruiter, D. J., Evers, S., Koopman, J. P.,    and de Witte, T. (2001). Production of anti-CD3 and anti-CD7 ricin    A-immunotoxins for a clinical pilot study. Int. J. Pharm. 221,    175-186.-   Papac, D. I., Hoyes, J., and Tomer, K. B. (1994). Epitope mapping of    the gastrin-releasing peptide/anti-bombesin monoclonal antibody    complex by proteolysis followed by matrix-assisted laser desorption    ionization mass spectrometry. Protein Sci. 3, 1485-1492.-   Park, L. S., Martin, U., Garka, K., Gliniak, B., Di Santo, J. P.,    Muller, W., Largaespada, D. A., Copeland, N. G., Jenkins, N. A.,    Farr, A. G., et al. (2000). Cloning of the murine thymic stromal    lymphopoietin (TSLP) receptor: Formation of a functional heteromeric    complex requires interleukin 7 receptor. J. Exp. Med. 192, 659-670.-   Paus, D., and Winter, G. (2006). Mapping epitopes and antigenicity    by site-directed masking. Proc. Natl. Acad. Sci. U.S.A. 103,    9172-9177.-   Poirier, N., Haudebourg, T., Brignone, C., Dilek, N., Hervouet, J.,    Minault, D., Coulon, F., de Silly, R. V., Triebel, F., Blancho, G.,    et al. (2011). Antibody-mediated depletion of lymphocyte-activation    gene-3 (LAG-3(+))-activated T lymphocytes prevents delayed-type    hypersensitivity in non-human primates. Clin. Exp. Immunol. 164,    265-274.-   Racapé, M., Vanhove, B., Soulillou, J.-P., and Brouard, S. (2009).    Interleukin 7 receptor alpha as a potential therapeutic target in    transplantation. Arch. Immunol. Ther. Exp. (Warsz.) 57, 253-261.-   Rader, C., Cheresh, D. A., and Barbas, C. F. (1998). A phage display    approach for rapid antibody humanization: designed combinatorial V    gene libraries. Proc. Natl. Acad. Sci. U.S.A. 95, 8910-8915.-   Reche, P. A., Soumelis, V., Gorman, D. M., Clifford, T., Liu Mr,    null, Travis, M., Zurawski, S. M., Johnston, J., Liu, Y. J., Spits,    H., et al. (2001). Human thymic stromal lymphopoietin preferentially    stimulates myeloid cells. J. Immunol. Baltim. Md 1950 167, 336-343.-   Risberg, K., Fodstad, Ø., and Andersson, Y. (2011). Synergistic    anticancer effects of the 9.2.27PE immunotoxin and ABT-737 in    melanoma. PloS One 6, e24012.-   Roan, F., Bell, B. D., Stoklasek, T. A., Kitajima, M., Han, H., and    Ziegler, S. F. (2012). The multiple facets of thymic stromal    lymphopoietin (TSLP) during allergic inflammation and beyond. J.    Leukoc. Biol. 91, 877-886.-   Rochman, Y., Kashyap, M., Robinson, G. W., Sakamoto, K.,    Gomez-Rodriguez, J., Wagner, K.-U., and Leonard, W. J. (2010).    Thymic stromal lymphopoietin-mediated STAT5 phosphorylation via    kinases JAK1 and JAK2 reveals a key difference from IL-7-induced    signaling. Proc. Natl. Acad. Sci. U.S.A. 107, 19455-19460.-   Rosok, M. J., Yelton, D. E., Harris, L. J., Bajorath, J.,    Hellström, K. E., Hellström, I., Cruz, G. A., Kristensson, K., Lin,    H., Huse, W. D., et al. (1996). A combinatorial library strategy for    the rapid humanization of anticarcinoma BR96 Fab. J. Biol. Chem.    271, 22611-22618.-   Schlehuber, S., Skerra, A. (2002). Tuning ligand affinity,    specificity, and folding stability of an engineered lipocalin    variant—a so-called ‘anticalin’—using a molecular random approach.    Biophys Chem. 2002 May 2; 96(2-3):213-28-   Shaw, A. S., and Dustin, M. L. (1997). Making the T cell receptor go    the distance: a topological view of T cell activation. Immunity 6,    361-369.-   Shinohara, T., Nemoto, Y., Kanai, T., Kameyama, K., Okamoto, R.,    Tsuchiya, K., Nakamura, T., Totsuka, T., Ikuta, K., and Watanabe, M.    (2011). Upregulated IL-7 receptor α expression on colitogenic memory    CD4+ T cells may participate in the development and persistence of    chronic colitis. J. Immunol. Baltim. Md 1950 186, 2623-2632.-   Shochat, C., Tal, N., Bandapalli, O. R., Palmi, C., Ganmore, I., te    Kronnie, G., Cario, G., Cazzaniga, G., Kulozik, A. E., Stanulla, M.,    et al. (2011). Gain-of-function mutations in interleukin-7    receptor-α (IL7R) in childhood acute lymphoblastic leukemias. J.    Exp. Med. 208, 901-908.-   Skerra, A. (2008). Alternative binding proteins:    anticalins—harnessing the structural plasticity of the lipocalin    ligand pocket to engineer novel binding activities. FEBS J. 2008    June; 275(11):2677-83. doi: 10.1111/j.1742-4658.2008.06439.x. Epub    2008 Apr. 24.-   Suckau, D., Köhl, J., Karwath, G., Schneider, K., Casaretto, M.,    Bitter-Suermann, D., and Przybylski, M. (1990). Molecular epitope    identification by limited proteolysis of an immobilized    antigen-antibody complex and mass spectrometric peptide mapping.    Proc. Natl. Acad. Sci. U.S.A. 87, 9848-9852-   Taylor, B. C., Zaph, C., Troy, A. E., Du, Y., Guild, K. J.,    Comeau, M. R., and Artis, D. (2009). TSLP regulates intestinal    immunity and inflammation in mouse models of helminth infection and    colitis. J. Exp. Med. 206, 655-667.-   Teeling, J. L., Mackus, W. J. M., Wiegman, L. J. J. M., van den    Brakel, J. H. N., Beers, S. A., French, R. R., van Meerten, T.,    Ebeling, S., Vink, T., Slootstra, J. W., et al. (2006). The    biological activity of human CD20 monoclonal antibodies is linked to    unique epitopes on CD20. J. Immunol. Baltim. Md 1950 177, 362-371.-   Timmerman, P., Puijk, W. C., and Meloen, R. H. (2007). Functional    reconstruction and synthetic mimicry of a conformational epitope    using CLIPS technology. J. Mol. Recognit. JMR 20, 283-299.-   Walsh, S. T. R. (2012). Structural insights into the common γ-chain    family of cytokines and receptors from the interleukin-7 pathway.    Immunol. Rev. 250, 303-316.-   Watanabe, N., Wang, Y.-H., Lee, H. K., Ito, T., Wang, Y.-H., Cao,    W., and Liu, Y.-J. (2005a). Hassall's corpuscles instruct dendritic    cells to induce CD4+CD25+ regulatory T cells in human thymus. Nature    436, 1181-1185.-   Watanabe, N., Hanabuchi, S., Marloie-Provost, M.-A., Antonenko, S.,    Liu, Y.-J., and Soumelis, V. (2005b). Human TSLP promotes CD40    ligand-induced IL-12 production by myeloid dendritic cells but    maintains their Th2 priming potential. Blood 105, 4749-4751.-   Ye, J., Ma, N., Madden, T. L., and Ostell, J. M. (2013). IgBLAST: an    immunoglobulin variable domain sequence analysis tool. Nucleic Acids    Res. 41, W34-W40.-   Ying, S., O'Connor, B., Ratoff, J., Meng, Q., Fang, C., Cousins, D.,    Zhang, G., Gu, S., Gao, Z., Shamji, B., et al. (2008). Expression    and cellular provenance of thymic stromal lymphopoietin and    chemokines in patients with severe asthma and chronic obstructive    pulmonary disease. J. Immunol. Baltim. Md 1950 181, 2790-2798.-   Zhi, K., Li, M., Zhang, X., Gao, Z., Bai, J., Wu, Y., Zhou, S., Li,    M., and Qu, L. (2014). α4β7 Integrin (LPAM-1) is upregulated at    atherosclerotic lesions and is involved in atherosclerosis    progression. Cell. Physiol. Biochem. Int. J. Exp. Cell. Physiol.    Biochem. Pharmacol. 33, 1876-1887.-   Zhong, J., Sharma, J., Raju, R., Palapetta, S. M., Prasad, T. S. K.,    Huang, T.-C., Yoda, A., Tyner, J. W., van Bodegom, D., Weinstock, D.    M., et al. (2014). TSLP signaling pathway map: a platform for    analysis of TSLP-mediated signaling. Database J. Biol. Databases    Curation 2014, bau007.

1-19. (canceled)
 20. A method for treating a pathological condition, themethod comprising: administering an effective amount of a compositioncomprising an anti-human CD127 agent that antagonizes interleukin-7receptor (IL-7R) signaling induced by interleukin-7 (IL7) to a patientwith said pathological condition; wherein the pathological condition isa cancer, an allergic disease, a respiratory disease, a disease relatedto transplantation, or a pathological condition involving the activationor proliferation of CD127 positive cells; wherein said anti-human CD127agent comprises an antibody or an antigen-binding fragment thereof whichbinds specifically to human CD127, wherein said antibody orantigen-binding fragment thereof comprises a VH chain comprising thefollowing amino acid sequences: (a) VHCDR1 of SEQ ID NO: 10; (b) VHCDR2of SEQ ID NO: 12; and (c) VHCDR3 of SEQ ID NO: 14 or of SEQ ID NO: 48;and wherein said antibody or antigen-binding fragment thereof comprisesa VL chain comprising the following amino acid sequences: (d) VLCDR1 ofSEQ ID NO: 16 or of SEQ ID NO: 50; (e) VLCDR2 of SEQ ID NO: 18 or of SEQID NO: 52; and (f) VLCDR3 of SEQ ID NO:
 20. 21. The method according toclaim 20, wherein activation or proliferation of CD127 positive cells isinhibited in the patient.
 22. The method according to claim 20, whereinthe composition further comprises an additional active ingredient,wherein the additional active ingredient is an antibody targetingT-cells or a recombinant protein or antibody targeting accessory cells.23. The method according to claim 22, wherein the additional activeingredient has a therapeutic immunomodulatory effect on cells involvedin an autoimmune disease, an allergic disease, leukemia, acutelymphoblastic leukemia, lymphoma, a chronic viral infection, aninflammatory disease, transplantation, or a respiratory disease.
 24. Themethod according to claim 22, wherein the antibody targeting T-cells isan anti-CD3, anti-ICOS, or anti-CD28 antibody, wherein the recombinantprotein is CTLA4Ig, or wherein the antibody is an anti-CD40 antibody.25. The method according to claim 20, wherein the anti-human CD127 agentis administered in a combination or in an add-on therapeutic regimen ina patient in need thereof.
 26. The method according to claim 20, whereinthe antibody or antigen-binding fragment thereof is covalently attachedto a chemical group or a biological group.
 27. The method according toclaim 20, wherein the anti-human CD127 agent is a chimeric antibody or ahumanized antibody or a deimmunized antibody.
 28. The method accordingto claim 20, wherein the composition is a pharmaceutical compositioncomprising the anti-human CD127 agent and a pharmaceutical vehicle. 29.The method according to claim 20, wherein the antibody orantigen-binding fragment thereof comprises sixcomplementarity-determining regions (CDRs) consisting of the amino acidsequences VHCDR1 SEQ ID NO: 10, VHCDR2 SEQ ID NO: 12, VHCDR3 SEQ ID NO:48, VLCDR1 SEQ ID NO: 50, VLCDR2 SEQ ID NO: 52, and VLCDR3 SEQ ID NO:20.
 30. The method according to claim 20, wherein the antibody orantigen-binding fragment thereof disrupts the binding of CD127 to the γccommon chain of cytokine receptors.
 31. The method according to claim20, wherein the antibody or antigen-binding fragment thereof does notincrease the maturation of dendritic cells induced by Thymic StromalLymphopoietin (TSLP).
 32. The method according to claim 20, wherein theantibody or antigen-binding fragment thereof does not induceinternalization of CD127 in cells incubated with said antibody orantigen-binding fragment thereof as compared to cells incubated in theabsence of said antibody or antigen-binding fragment thereof.
 33. Themethod according to claim 20, wherein the antibody or antigen-bindingfragment thereof in presence of IL7 does not significantly decrease thecell surface expression of CD127, and/or inhibits the internalization ofCD127, as compared to cells incubated with interleukin 7 (IL-7) and inthe absence of said antibody or antigen-binding fragment thereof. 34.The method according to claim 20, wherein the antibody orantigen-binding fragment thereof comprises: (i) a heavy chain comprisingthe amino acid sequence of SEQ ID NO: 22, SEQ ID NO: 36, SEQ ID NO: 38,or SEQ ID NO: 40; and (ii) a light chain comprising the amino acidsequence of SEQ ID NO: 24, SEQ ID NO: 42, SEQ ID NO: 44, or SEQ ID NO:46.
 35. The method according to claim 20, wherein the antibody orantigen-binding fragment thereof comprises: (i) a heavy chain with theamino acid sequence of SEQ ID NO: 2, SEQ ID NO: 6, or SEQ ID NO: 54; and(ii) a light chain with the amino acid sequence of SEQ ID NO: 4 or SEQID NO: 56.